ZKC

Organic electronics have been developed according to an orthodox doctrine advocating “all-printed’’, “all-organic’’ and “ultra-low-cost’’ primarily targeting various e-paper applications. In order to harvest from the great opportunities afforded with organic electronics potentially operating as communication and sensor outposts within existing and future complex communication infrastructures, high-quality computing and communication protocols must be integrated with the organic electronics. Here, we debate and scrutinize the twinning of the signal-processing capability of traditional integrated silicon chips with organic electronics and sensors, and to use our body as a natural local network with our bare hand as the browser of the physical world. The resulting platform provides a body network, i.e., a personalized web, composed of e-label sensors, bioelectronics, and mobile devices that together make it possible to monitor and record both our ambience and health-status parameters, supported by the ubiquitous mobile network and the resources of the “cloud”.

The twinning of the signal-processing capability of traditional integrated silicon chips with printed organic electronics and sensors is debated and scrutinized, and the use of the human body as a natural local network with the bare hands as the browser of the physical world is discussed.

Planar heterojunction perovskite solar cells with a high efficiency up to 17.76% are fabricated by modifying the compact TiO₂ (c-TiO₂) with a [6,6]-phenyl-C₆₁-butyric acid (PCBA) monolayer. High quality CH₃NH₃PbI₃ films can be easily fabricated on PCBA-modified c-TiO₂ substrates by a one-step solution processing method. Significant improvements of the device parameters are observed after PCBA modification. A high open-circuit voltage (V_oc) of 1.16 V has been achieved, indicating that the PCBA monolayer can act as a hole blocking layer to reduce the trap site density atop the c-TiO₂ and the hole recombination at the c-TiO₂/perovskite interface. The enhancement of the fill factor, as well as the partial quenching of the fluorescence of perovskite after modification with PCBA, reveals that the charge extraction is improved.

Planar CH₃NH₃PbI₃ perovskite solar cells with a power conversion efficiency (PCE) of 17.76% with an open-circuit voltage of 1.16 V are fabricated by using [6,6]-phenyl-C₆₁-butyric acid (PCBA) monolayer as a hole blocking layer between compact TiO₂ layer and perovskite active layer. Compared with the control devices, PCBA monolayer modified solar cells show an 80% enhancement of PCE.

Flexible and light-weight solar cells are important because they not only supply power to wearable and portable devices, but also reduce the transportation and installation cost of solar panels. High-efficiency organometal halide perovskite solar cells can be fabricated by a low-temperature solution process, and hence are promising for flexible-solar-cell applications. Here, the development of perovskite solar cells is briefly discussed, followed by the merits of organometal halide perovskites as promising candidates as high-efficiency, flexible, and light-weight photovoltaic materials. Afterward, recent developments of flexible solar cells based on perovskites are reviewed.

Organometal halide perovskites are promising photovoltaic materials for flexible and light-weight solar cells. The high power conversion efficiency (over 15%) of flexible perovskite solar cells is not only useful to power wearable and portable devices, but also promising for off-grid and on-grid photovoltaic applications. Recent progress in flexible perovskite solar cells is discussed.

Flexible electronic devices are necessary for applications involving unconventional interfaces, such as soft and curved biological systems, in which traditional silicon-based electronics would confront a mechanical mismatch. Biological polymers offer new opportunities for flexible electronic devices by virtue of their biocompatibility, environmental benignity, and sustainability, as well as low cost. As an intriguing and abundant biomaterial, silk offers exquisite mechanical, optical, and electrical properties that are advantageous toward the development of next-generation biocompatible electronic devices. The utilization of silk fibroin is emphasized as both passive and active components in flexible electronic devices. The employment of biocompatible and biosustainable silk materials revolutionizes state-of-the-art electronic devices and systems that currently rely on conventional semiconductor technologies. Advances in silk-based electronic devices would open new avenues for employing biomaterials in the design and integration of high-performance biointegrated electronics for future applications in consumer electronics, computing technologies, and biomedical diagnosis, as well as human–machine interfaces.

Silk fibroin is an ancient biomaterial with exquisite mechanical, optical, and electrical properties. Its intriguing properties and environmental benignity render silk fibroin compelling for the advancement of next-generation biocompatible and biodegradable flexible electronic devices.

To capture the essence of the rapid progress in optical engineering exploited in high-performance polymer solar cells (PSCs), a comprehensive overview focusing on recent developments and achievements in PSC electrode engineering is provided in this review. To date, various kinds of electrode materials and geometries are exploited to enhance light-trapping in devices through distinct optical strategies. In addition to the widely used nanostructured electrodes that induce plasmonic-enhanced light absorption, planar ultra-thin metal films also have attracted significant attention due to their remarkably reflective transparent properties that beget efficient optical microcavities. These microcavities confine incident light with resonant frequencies between two reflective electrodes due to optically coherent interference, boosting the light absorption of thin-film PSCs while maintaining efficient charge dissociation and extraction. After reviewing the challenges in developing high-performance microcavity-enhanced PSCs (MCPSCs), we discuss strategies to improve MCPSC performance further to showcase the potential of harnessing microcavity resonance effects in thin-film PSCs.

Recent developments and achievements in polymer solar cell electrode engineering are reviewed. Planar ultra-thin metal electrodes are highlighted because they can induce optically coherent interference to confine incident light with resonant frequencies within the photovoltaic cell. Such optical microcavities can boost the light absorption of thin-film PSCs while maintaining efficient charge dissociation and extraction.