A record breaking PCE of 12.1% is achieved by incorporating 25 wt% of DR3TSBDT into a PTB7-Th:PC71BM host matrix.

Organic-inorganic hybrid photo-detectors with a self-sufficient mode of operation represent a research area of great current interest. In most efficient photodetectors and optoelectronic devices compound semiconductors containing toxic elements such as Cd, As, Te, S, Se etc. are used and these are also expensive. Hence there is also a rapidly growing interest in replacing these with environmentally friendly and earth-abundant materials. Herein, we report a facile solution-processed fabrication of a self-powered organic-inorganic hybrid photodetector using n-type oriented ZnO nanorods and p-type Spiro-MeOTAD semiconductor. ZnO is eco-friendly and earth-abundant, and Spiro-MeOTAD is non-hazardous. We show that the latter has far less toxicity than the toxic elements stated above. This visible blind UV photodetector shows high sensitivity (10(2)) and a UV/visible rejection ratio of 300. It also exhibits fast response times of τ(rise) ~ 200 μs and τ(fall) ~ 950 μs. Importantly, with a small modification of nitrogen incorporation in ZnO one can also realize a highly-sensitive self-powered visible light photodetector with at least 1000% (or higher) improvements in quality factors (photocurrent/sensitivity/response time) as compared to previously reported organic-inorganic hybrid photo-detectors based on metal-chalcogenides (CdS-PANI or CuInSe2-P3HT). Interestingly, the broadband sensitivity of such N:ZnO-Spiro-MeOTAD photodiode enables sensing of low intensity (~28 μW cm(-2)) ambient white light with a high photocurrent density of 120 nA cm(-2) making it an efficient ambient white light detector.

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Compared with conventional organic solar cells (OSCs) based on single donor–acceptor pairs, terpolymer‐ and ternary‐based OSCs featuring multiple donor–acceptor pairs are promising strategies for enhancing the performance while maintaining an easy and simple synthetic process. Using multiple donor–acceptor pairs in the active layer, the key photovoltaic parameters (i.e., short‐circuit current density, open‐circuit voltage, and fill factor) governing the OSC characteristics can be simultaneously or individually improved by positive changes in light‐harvesting ability, molecular energy levels, and blend morphology. Here, these three major contributions are discussed with the aim of offering in‐depth insights in combined terpolymers and ternary systems. Recent exemplary cases of OSCs with multiple donor–acceptor pairs are summarized and more advanced research and perspectives for further developments in this field are highlighted.

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In this study, the solubility properties of a given ternary blend set, with two donors (poly(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′] dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl (PTB7-Th) and benzo[1,2-b;4,5-b′]dithiophene-based small molecule (DR3TSBDT)) and one acceptor ([6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM)), in a series of solvents are determined, and active material-solvent interactions are used as an aid for finding suitable nonchlorinated solvents to achieve effective ternary organic solar cells (OSCs) based on PTB7-Th:DR3TSBDT:PC 71 BM. An exceptional power conversion efficiency (PCE) as high as 12.3% (certified 11.94%) is obtained using the developed nonhalogenated processing system. In-depth investigations (morphology, charge mobility, recombination dynamics, and OSC characteristics) uncover the underlying structure-property relationships as a function of the chosen nonhalogenated systems. Another intriguing finding of this study is the formation of a cubic bimolecular crystal structure of PTB7-Th:PC 71 BM in a nonhalogenated system, which is the first such demonstration in blend films. This sheds light upon the fact that the physical properties of a material applied from different solutions may surpass the variation in the properties between two material having totally different molecular structure. Therefore, this work not only offers important scientific insights into developing highly efficient and eco-friendly OSCs but also improves our understanding of achievable bimolecular crystals with an intercalated structure.

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