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12 Jul 01:18

Efficient and stable tandem luminescent solar concentrators based on carbon dots and perovskite quantum dots

Publication date: August 2018

Source: Nano Energy, Volume 50

Author(s): Haiguang Zhao, Daniele Benetti, Xin Tong, Hui Zhang, Yufeng Zhou, Guiju Liu, Dongling Ma, Shuhui Sun, Zhiming M. Wang, Yiqian Wang, Federico Rosei

Abstract

Luminescent solar concentrator (LSC) can serve as large-area sunlight collectors, suitable for applications in building-integrated high-efficiency and low-cost photovoltaics. Inorganic perovskite quantum dots (QDs) are promising candidates as absorbers/emitters in LSCs, due to their high quantum yields (close to 100%), possibility of tuning size and chemical composition and broad absorption spectrum and high absorption coefficient. However, despite their great potential for technological development, LSCs fabricated using colloidal perovskite QDs still face major challenges such as low optical efficiency and limited long-term stability. Here we report a large-area (~ 100 cm2) tandem LSC based on nearly reabsorption-free carbon dots (C-dots) and inorganic mixed-halide perovskite QDs spectrally-tuned for optimal solar-spectrum splitting. The as-fabricated semi-transparent device, without involving any complicated processes, exhibits an external optical efficiency of ~ 3% under sunlight illumination (100 mW/cm2), which represents a 27% enhancement in efficiency over single layer LSCs based on CsPb(BrxI1-x)3 QDs and 117% over CsPb(ClxBr1-x)3 QDs. Our work shows that the addition of C-dots can dramatically enhance the long-term durability of LSC devices based on perovskite QDs due to their excellent photostability and simultaneous absorption of ultraviolet light.

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12 Jul 01:09

Designing ternary blend all-polymer solar cells with an efficiency of over 10% and a fill factor of 78%

Publication date: September 2018

Source: Nano Energy, Volume 51

Author(s): Zhenye Li, Lei Ying, Ruihao Xie, Peng Zhu, Ning Li, Wenkai Zhong, Fei Huang, Yong Cao

Abstract

In recent years, ternary blend bulk-heterojunction (BHJ) all-polymer solar cells have been gradually developed to better utilize the solar irradiance spectrum. However, power conversion efficiencies remain below 10%, mainly because of the low fill factor. Generally, the fill factor of all-polymer solar cells is limited mainly by the competition between the recombination and extraction of free charges. Here, we design advanced ternary blend all-polymer solar cells with a high fill factor of 78%, thus demonstrating how such recombination thresholds can be overcome. These results can be attributed to the high and balanced bulk charge mobility, reduced recombination, and optimized morphology, as well as the intimate mixing properties of the two donors in the photoactive layer.

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12 Jul 01:08

Printing organic photovoltaics

by Giulia Tregnago

Printing organic photovoltaics

Printing organic photovoltaics, Published online: 10 July 2018; doi:10.1038/s41560-018-0212-2

Printing organic photovoltaics
14 Jun 01:23

Relating open-circuit voltage losses to the active layer morphology and contact selectivity in organic solar cells

J. Mater. Chem. A, 2018, 6,12574-12581
DOI: 10.1039/C8TA01195H, Paper
Zheng Tang, Jing Wang, Armantas Melianas, Yang Wu, Renee Kroon, Weiwei Li, Wei Ma, Mats R. Andersson, Zaifei Ma, Wanzhu Cai, Wolfgang Tress, Olle Inganas
By manipulating the active-layer morphologies in OSCs, we achieve different open-circuit-voltages without affecting the energy of charge-transfer state.
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13 Jun 01:34

A fluorine-modulated bulk-phase heterojunction and tolerance factor for enhanced performance and structure stability of cesium lead halide perovskite solar cells

J. Mater. Chem. A, 2018, 6,13263-13270
DOI: 10.1039/C8TA02899K, Paper
Lin Fu, Yanan Zhang, Bohong Chang, Bo Li, Shujie Zhou, Luyuan Zhang, Longwei Yin
The α-/δ-phase heterojunction induced by fluorine builds a matched band structure, exhibiting a champion PCE of 10.26% with improved stability.
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13 Jun 01:34

Control over Self‐Doping in High Band Gap Perovskite Films

by Michael Kulbak , Igal Levine , Einav Barak‐Kulbak , Satyajit Gupta , Arava Zohar , Isaac Balberg , Gary Hodes , David Cahen
Advanced Energy Materials, EarlyView.
13 Jun 01:33

Highly Efficient 2D/3D Hybrid Perovskite Solar Cells via Low‐Pressure Vapor‐Assisted Solution Process

by Ming‐Hsien Li , Hung‐Hsiang Yeh , Yu‐Hsien Chiang , U‐Ser Jeng , Chun‐Jen Su , Hung‐Wei Shiu , Yao‐Jane Hsu , Nobuhiro Kosugi , Takuji Ohigashi , Yu‐An Chen , Po‐Shen Shen , Peter Chen , Tzung‐Fang Guo
Advanced Materials, EarlyView.
13 Jun 01:33

Grain‐Boundary “Patches” by In Situ Conversion to Enhance Perovskite Solar Cells Stability

by Lang Liu , Sheng Huang , Yue Lu , Pengfei Liu , Yizhou Zhao , Congbo Shi , Siyu Zhang , Jiafeng Wu , Haizheng Zhong , Manling Sui , Huanping Zhou , Haibo Jin , Yujing Li , Qi Chen
Advanced Materials, EarlyView.
13 Jun 01:33

Room‐Temperature Triple‐Ligand Surface Engineering Synergistically Boosts Ink Stability, Recombination Dynamics, and Charge Injection toward EQE‐11.6% Perovskite QLEDs

by Jizhong Song , Jinhang Li , Leimeng Xu , Jianhai Li , Fengjuan Zhang , Boning Han , Qingsong Shan , Haibo Zeng
Advanced Materials, EarlyView.
13 Jun 01:10

[ASAP] Reduced Charge-Transfer Threshold in Dye-Sensitized Solar Cells with an Au@Ag/N3/n-TiO2 Structure As Revealed by Surface-Enhanced Raman Scattering

by Xiaolei Wang, Xiao Xia Han, Hao Ma, Peng Li, Xueliang Li, Yasutaka Kitahama, Bing Zhao, Yukihiro Ozaki

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.8b02197
13 Jun 01:09

[ASAP] Humidity-Induced Photoluminescence Hysteresis in Variable Cs/Br Ratio Hybrid Perovskites

by John M. Howard, Elizabeth M. Tennyson, Sabyasachi Barik, Rodrigo Szostak, Edo Waks, Michael F. Toney, Ana F. Nogueira, Bernardo R. A. Neves, Marina S. Leite

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The Journal of Physical Chemistry Letters
DOI: 10.1021/acs.jpclett.8b01357
12 Jun 08:43

[ASAP] Predictable Particle Engineering: Programming the Energy Level, Carrier Generation, and Conductivity of Core–Shell Particles

by Conghui Yuan, Tong Wu, Jie Mao, Ting Chen, Yuntong Li, Min Li, Yiting Xu, Birong Zeng, Weiang Luo, Lingke Yu, Gaofeng Zheng, Lizong Dai

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Journal of the American Chemical Society
DOI: 10.1021/jacs.8b03010
12 Jun 08:38

[ASAP] Inter-Backbone Charge Transfer as Prerequisite for Long-Range Conductivity in Perylene Bisimide Hydrogels

by Max Burian, Francesco Rigodanza, Nicola Demitri, Luka D?ord?evic, Silvia Marchesan, Tereza Steinhartova, Ilse Letofsky-Papst, Ivan Khalakhan, Eléonore Mourad, Stefan A. Freunberger, Heinz Amenitsch, Maurizio Prato, Zois Syrgiannis

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ACS Nano
DOI: 10.1021/acsnano.8b01689
12 Jun 08:35

[ASAP] Relating Photoelectrochemistry and Wettability of Sputtered Cu- and N-Doped TiO2 Thin Films via an Integrated Approach

by Corrado Garlisi, Chia-Yun Lai, Leslie George, Matteo Chiesa, Giovanni Palmisano

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.8b03650
12 Jun 08:32

[ASAP] Enhancing Luminescence and Photostability of CsPbBr3 Nanocrystals via Surface Passivation with Silver Complex

by Hongbo Li, Yang Qian, Xing Xing, Jianfeng Zhu, Xinyu Huang, Qiang Jing, Weihua Zhang, Chunfeng Zhang, Zhenda Lu

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.8b04569
12 Jun 08:28

[ASAP] “Intact” Carrier Doping by Pump–Pump–Probe Spectroscopy in Combination with Interfacial Charge Transfer: A Case Study of CsPbBr3 Nanocrystals

by Junhui Wang, Tao Ding, Jing Leng, Shengye Jin, Kaifeng Wu

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The Journal of Physical Chemistry Letters
DOI: 10.1021/acs.jpclett.8b01132
12 Jun 08:26

[ASAP] Tuning the Optoelectronic Properties of Two-Dimensional Hybrid Perovskite Semiconductors with Alkyl Chain Spacers

by Claudio Quarti, Nadège Marchal, David Beljonne

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The Journal of Physical Chemistry Letters
DOI: 10.1021/acs.jpclett.8b01309
12 Jun 08:24

[ASAP] Novel Plasma-Assisted Low-Temperature-Processed SnO2 Thin Films for Efficient Flexible Perovskite Photovoltaics

by Anand S. Subbiah, Nripan Mathews, Subodh Mhaisalkar, Shaibal K. Sarkar

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ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00692
12 Jun 08:24

[ASAP] Nonfullerene Polymer Solar Cells Based on a Main-Chain Twisted Low-Bandgap Acceptor with Power Conversion Efficiency of 13.2%

by Weiping Wang, Baofeng Zhao, Zhiyuan Cong, Yuan Xie, Haimei Wu, Quanbin Liang, Sha Liu, Feng Liu, Chao Gao, Hongbin Wu, Yong Cao

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ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00627
12 Jun 08:23

Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency

by Florent Sahli

Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency

Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency, Published online: 11 June 2018; doi:10.1038/s41563-018-0115-4

An optimized two-step deposition process allows the formation of uniform layers of metal halide perovskites on textured silicon layers, enabling tandem silicon/perovskite solar cells with improved optical design and efficiency.
12 Mar 14:39

Perovskite Solar Cells: All-Carbon-Electrode-Based Endurable Flexible Perovskite Solar Cells (Adv. Funct. Mater. 11/2018)

by Qiang Luo, He Ma, Qinzhi Hou, Yingxiang Li, Jing Ren, Xuezeng Dai, Zhibo Yao, Yu Zhou, Lichen Xiang, Huayun Du, Hongcai He, Ning Wang, Kaili Jiang, Hong Lin, Huaiwu Zhang, Zhanhu Guo
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A durable flexible perovskite solar cell that employs graphene as transparent anode and carbon nanotubes as cathode is successfully developed by Ning Wang, Kaili Jiang, Hong Lin, Zhanhu Guo, and co-workers in article number 1706777. All-carbon-electrode-based devices exhibit promising efficiency, excellent flexibility, and stability, providing a new avenue for construction of cheap and large-scale flexible perovskite solar cells.

08 Mar 13:24

From Nanostructural Evolution to Dynamic Interplay of Constituents: Perspectives for Perovskite Solar Cells

by Taehyun Hwang, Byungho Lee, Jinhyun Kim, Sangheon Lee, Bumjin Gil, Alan Jiwan Yun, Byungwoo Park

Abstract

Moving away from the high-performance achievements in organometal halide perovskite (OHP)-based optoelectronic and photovoltaic devices, intriguing features have been reported in that photocarriers and mobile ionic species within OHPs interact with light, electric fields, or a combination of both, which induces both spatial and temporal changes of optoelectronic properties in OHPs. Since it is revealed that the transport of photocarriers and the migration of ionic species are affected not only by each other but also by the inhomogeneous character, which is a consequence of the route selected to deposit OHPs, understanding the nanostructural evolution during OHP deposition, in terms of the resultant structural defects, electronic traps, and nanoscopic charge behaviors, will be valuable. Investigation of the film-growth mechanisms and strategies adopted to realize OHP films with less-defective large grains is of central importance, considering that single-crystalline OHPs have exhibited the most beneficial properties, including carrier lifetimes. Critical factors governing the behavior of photocarriers, mobile ionic species, and nanoscale optoelectronic properties resulting from either or all of them are further summarized, which may potentially limit or broaden the optoelectronic and photovoltaic applications of OHPs. Through inspection of the recent advances, a comprehensive picture and future perspective of OHPs are provided.

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With giant steps regarding organometal halide perovskite (OHP)-based optoelectronic and photovoltaic devices having been made, OHPs are being driven toward applications beyond photovoltaics. Recent progress regarding the various characteristics of OHPs and their impact on photovoltaic devices are reviewed, from microstructural evolution coupled with nanostructural/electronic disorder to photoinduced charge-carrier dynamics; the implications for potential applications are also outlined.

05 Mar 12:42

Stable hybrid organic-inorganic halide perovskites for photovoltaics from ab initio high-throughput calculations

J. Mater. Chem. A, 2018, 6,6463-6475
DOI: 10.1039/C7TA08992A, Paper
Sabine Korbel, Miguel A. L. Marques, Silvana Botti
By means of high-throughput first-principles calculations, we screen a large number of hypothetical hybrid perovskite compounds by stability, band gap and effective mass to find the best perovskites for photovoltaics.
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05 Mar 01:39

Bilateral Interface Engineering toward Efficient 2D–3D Bulk Heterojunction Tin Halide Lead-Free Perovskite Solar Cells

by Chenxin Ran, Jun Xi, Weiyin Gao, Fang Yuan, Ting Lei, Bo Jiao, Xun Hou and Zhaoxin Wu

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ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00085
05 Mar 01:39

HyPe-2017: A Discussion Meeting on Hybrid Perovskites

by Priya Mahadevan
ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00247
05 Mar 01:39

Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV

by Jérémie Werner, Gizem Nogay, Florent Sahli, Terry Chien-Jen Yang, Matthias Bräuninger, Gabriel Christmann, Arnaud Walter, Brett A. Kamino, Peter Fiala, Philipp Löper, Sylvain Nicolay, Quentin Jeangros, Bjoern Niesen and Christophe Ballif

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ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00089
05 Mar 01:39

[ASAP] Efficient and Selective Photocatalytic Oxidation of Benzylic Alcohols with Hybrid Organic–Inorganic Perovskite Materials

by Haowei Huang, Haifeng Yuan, Kris P. F. Janssen, Guillermo Solís-Fernández, Ying Wang, Collin Y. X. Tan, Dries Jonckheere, Elke Debroye, Jinlin Long, Jelle Hendrix, Johan Hofkens, Julian A. Steele and Maarten B. J. Roeffaers

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ACS Energy Letters
DOI: 10.1021/acsenergylett.8b00131
04 Mar 06:34

Highly Efficient Tandem Organic Solar Cell Enabled by Environmentally Friendly Solvent Processed Polymeric Interconnecting Layer

by Kai Zhang, Baobing Fan, Ruoxi Xia, Xiang Liu, Zhicheng Hu, Honggang Gu, Shiyuan Liu, Hin-Lap Yip, Lei Ying, Fei Huang, Yong Cao

Abstract

In the field of organic solar cells (OSCs), tandem structure devices exhibit very attractive advantages for improving power conversion efficiency (PCE). In addition to the well researched novel pair of active layers in different subcells, the construction of interconnecting layer (ICL) also plays a critical role in achieving high performance tandem devices. In this work, a new way of achieving environmentally friendly solvent processed polymeric ICL by adopting poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-5,5′-bis(2,2′-thiophene)-2,6-naphthalene-1,4,5,8-tetracaboxylic-N,N′-di(2-ethylhexyl)imide] (PNDIT-F3N) blended with poly(ethyleneimine) (PEI) as the electron transport layer (ETL) and PEDOT:PSS as the hole transport layer is reported. It is found that the modification ability of PNDIT-F3N on PEDOT can be linearly tuned by the incorporation of PEI, which offers the opportunity to study the charge recombination behavior in ICL. At last, tandem OSC with highest PCE of 12.6% is achieved, which is one of the best tandem OSCs reported till now. These results offer a new selection for constructing efficient ICL in high performance tandem OSCs and guide the way of design new ETL materials for ICL construction, and may even be integrated in future printed flexible large area module device fabrication with the advantages of environmentally friendly solvent processing and thickness insensitivity.

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A new polymeric interconnecting layer (ICL) based on poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-5,5′-bis(2,2′-thiophene)-2,6-naphthalene-1,4,5,8-tetracaboxylic-N,N′-di(2-ethylhexyl)imide]: poly(ethyleneimine)/PEDOT:PSS is developed and applied for the fabrication of high performance tandem organic solar cells (OSCs). Tandem OSCs employing this ICL achieve a high power conversion efficiency of 12.6% with ICL thickness of 60 nm and even reach to 11.3% with ICL thickness of 140 nm.

04 Mar 06:34

Characterization of the Valence and Conduction Band Levels of n = 1 2D Perovskites: A Combined Experimental and Theoretical Investigation

by Scott Silver, Jun Yin, Hong Li, Jean-Luc Brédas, Antoine Kahn

Abstract

This study presents a combined experimental and theoretical study of the electronic structure of two 2D metal halide perovskite films. Ultraviolet and inverse photoemission spectroscopies are performed on solution-processed thin films of the n = 1 layered perovskite butylammonium lead iodide and bromide, BA2PbI4 and BA2PbBr4, characterized by optical absorption and X-ray diffraction, to determine their valence and conduction band densities of states, transport gaps, and exciton binding energies. The electron spectroscopy results are compared with the densities of states determined by density functional theory calculations. The remarkable agreement between experiment and calculation enables a detailed identification and analysis of the organic and inorganic contributions to the valence and conduction bands of these two hybrid perovskites. The electron affinity and ionization energies are found to be 3.1 and 5.8 eV for BA2PbI4, and 3.1 and 6.5 eV for BA2PbBr4. The exciton binding energies are estimated to be 260 and 300 meV for the two materials, respectively. The 2D lead iodide and bromide perovskites exhibit significantly less band dispersion and a larger density of states at the band edges than the 3D analogs. The effects of using various organic ligands are also discussed.

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Understanding the density of electronic states (DOS) in 2D metal halide perovskites is a crucial step in the investigation of the fundamental properties of these materials. This combined experimental–theoretical study via direct and inverse photoemission spectroscopy and density functional theory calculations maps out the various contributions from organic and inorganic constituents to the DOS of the materials.

01 Mar 12:48

Strong Depletion in Hybrid Perovskite p–n Junctions Induced by Local Electronic Doping

by Qingdong Ou, Yupeng Zhang, Ziyu Wang, Jodie A. Yuwono, Rongbin Wang, Zhigao Dai, Wei Li, Changxi Zheng, Zai-Quan Xu, Xiang Qi, Steffen Duhm, Nikhil V. Medhekar, Han Zhang, Qiaoliang Bao

Abstract

A semiconductor p–n junction typically has a doping-induced carrier depletion region, where the doping level positively correlates with the built-in potential and negatively correlates with the depletion layer width. In conventional bulk and atomically thin junctions, this correlation challenges the synergy of the internal field and its spatial extent in carrier generation/transport. Organic–inorganic hybrid perovskites, a class of crystalline ionic semiconductors, are promising alternatives because of their direct badgap, long diffusion length, and large dielectric constant. Here, strong depletion in a lateral p–n junction induced by local electronic doping at the surface of individual CH3NH3PbI3 perovskite nanosheets is reported. Unlike conventional surface doping with a weak van der Waals adsorption, covalent bonding and hydrogen bonding between a MoO3 dopant and the perovskite are theoretically predicted and experimentally verified. The strong hybridization-induced electronic coupling leads to an enhanced built-in electric field. The large electric permittivity arising from the ionic polarizability further contributes to the formation of an unusually broad depletion region up to 10 µm in the junction. Under visible optical excitation without electrical bias, the lateral diode demonstrates unprecedented photovoltaic conversion with an external quantum efficiency of 3.93% and a photodetection responsivity of 1.42 A W−1.

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Strong charge depletion in a lateral perovskite nanosheet p–n junction is reported with a large depletion width (>10 µm) and a high built-in potential (≈0.5 eV) through local electronic doping at the surface of individual CH3NH3PbI3 perovskite nanosheets. 2D electrostatics imaging further reveals a thickness dependence of the depletion width in the perovskite p–n junctions.