Chen Weijie

Publication date: Available online 19 June 2018
Source:Joule
Author(s): Hui Chen, Zhiming Hu, Huan Wang, Longzhu Liu, Pengjie Chao, Jianfei Qu, Wei Chen, Anhua Liu, Feng He
We synthesized a chlorinated benzothiadiazole-T4 polymer donor PBT4T-Cl, in which a chlorine atom had been introduced at the 4 position in the middle thiophene unit to fine-tune the energy level of the final polymers. Compared with its non-chlorinated analog, the PBT4T-Cl-based devices exhibited clear increases in open-circuit voltage and fill factor, achieving power conversion efficiencies (PCEs) up to 11.18% with simple synthesis, which is the highest PCE of the chlorinated polymer-based fullerene polymer solar cells (PSCs) reported to date. Grazing incident wide-angle X-ray scattering, atomic force microscopy, and transmission electron microscopy measurements revealed an optimized morphology of the spin-coated PBT4T-Cl blend films, which supported that chlorine substitution could promote the performance of PSCs. More importantly, the PBT4T-Cl-based devices showed superior stability, with a PCE of 8.16% after 50 days’ device storage. Through this research, the chlorination of low-band-gap polymers provides new insight into designing π-conjugated polymer semiconductors and realizing further enhancement of polymer solar cell efficiency as well as stability.

Graphical abstract

Teaser

We reported a chlorinated polymer donor PBT4T-Cl that showed a high PCE of 11.18%. The results demonstrated chlorination of the thiophene moiety could fine-tune the HOMO level of the corresponding polymer as well as the carrier mobility and morphologies of the blend film, eventually improving its photovoltaic properties as a donor without thermal annealing.

Publication date: 20 June 2018
Source:Joule, Volume 2, Issue 6
Author(s): Sheng-Yung Chang, Pei Cheng, Gang Li, Yang Yang
Polymer photovoltaics have become a promising alternative energy due to lightweight properties, environmental friendliness, and solution processability. Transparent organic photovoltaics in particular have been recently receiving more attention in the photovoltaics field due to their unique potential in future applications beyond mere harvesting of solar energy. This perspective is further enhanced by the recent developments of high-performance polymer photovoltaics (including infrared absorbing materials and devices) that could achieve superior visible transparency and power conversion efficiency. To realize high-performance transparent organic photovoltaics, the main strategy is to shift the active-layer absorption spectrum to the infrared region by designing new low-bandgap donors and non-fullerene acceptors, and to reduce the invalid absorption by developing new transparent electrode materials. The potential applications are diverse, especially for spectrum-sensitive ones such as the greenhouse in agriculture. Finally, some key research areas of transparent organic photovoltaics that may deserve further attention are discussed.

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Teaser

Because of an emergent demand for visible-spectrum applications in daily life, organic-based photovoltaics are thought to be a strong candidate to fulfill this need. This article concisely reviews the developments in polymer and small-molecule materials for achieving effective transparent photovoltaic devices and their potential applications in order to engender new ideas on achieving superior transparency, power conversion efficiency, and more practical uses.

Publication date: Available online 25 June 2018
Source:Joule
Author(s): Dianyi Liu, Chenchen Yang, Richard R. Lunt
Halide perovskite materials have emerged as a potential Si replacement with excellent photovoltaic properties. There has been growing interest in applying halide perovskites to semitransparent and spatially segmented transparent photovoltaics (TPVs) to enable a greater range of deployment routes. However, the continuous-band absorption of these semiconductors prevents near-infrared selective harvesting typically targeted for TPVs with the highest efficiency and transparency needed to meet the aesthetic demands of many potential applications. In this work, we demonstrate TPVs based on perovskite semiconductors where the band gap is sensitively tuned with a range of compositions to selectively harvest only ultraviolet photons with band gaps between 410 and 440 nm. This approach offers theoretical efficiencies up to 7% with >99% visible transparency when precisely targeting band gaps around 435 nm. Practical optimization of these perovskite cells could quickly yield TPVs with power conversion efficiencies rivaling state-of-the-art near-infrared harvesting TPVs today while also providing a route to higher-efficiency multi-junction TPVs.

Graphical abstract

Teaser

UV-harvesting transparent photovoltaic devices with halide perovskite light absorbers are demonstrated. The band gap is sensitively tuned with a range of compositions to selectively harvest only UV photons with band gaps between 410 and 440 nm. This approach offers theoretical efficiencies up to 7% with >99% visible transparency when precisely targeting band gaps around 435 nm. Practical optimization of these perovskite cells could quickly yield TPVs with PCEs rivaling state-of-the-art near-infrared-harvesting TPVs today while also providing a route to higher-efficiency multi-junction TPVs.

Small, Volume 14, Issue 31, August 2, 2018.

Advanced Functional Materials, Volume 28, Issue 26, June 27, 2018.

Advanced Energy Materials, Volume 8, Issue 24, August 27, 2018.

Advanced Materials, Volume 30, Issue 31, August 2, 2018.

Author Correction: III–V-on-silicon solar cells reaching 33% photoconversion efficiency in two-terminal configuration

Author Correction: III–V-on-silicon solar cells reaching 33% photoconversion efficiency in two-terminal configuration, Published online: 25 June 2018; doi:10.1038/s41560-018-0208-y

Author Correction: III–V-on-silicon solar cells reaching 33% photoconversion efficiency in two-terminal configuration

Advanced Functional Materials, EarlyView.

Advanced Functional Materials, Volume 28, Issue 33, August 15, 2018.

Advanced Functional Materials, EarlyView.

Advanced Functional Materials, EarlyView.

Advanced Functional Materials, Volume 28, Issue 32, August 8, 2018.

Advanced Energy Materials, Volume 8, Issue 23, August 16, 2018.

Advanced Energy Materials, Volume 8, Issue 23, August 16, 2018.

Advanced Energy Materials, Volume 8, Issue 23, August 16, 2018.

Advanced Energy Materials, Volume 8, Issue 23, August 16, 2018.

Advanced Energy Materials, Volume 8, Issue 23, August 16, 2018.

Advanced Functional Materials, Volume 28, Issue 31, August 1, 2018.