Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.160
Publication date: 20th April 2022
Fabrication of a stable low band-gap perovskite has always been proved challenging for photovoltaics application. The objectives of this work have been, developing a high quality low-bandgap perovskite with mixed tin-lead(Sn-Pb), optimizing the device, and making a semi-transparent structure as a photodiode.
The main bottlenecks of the aforementioned solar cells are the reduction of Sn2+ in the process which hinders the perovskite stability and the low Voc. The optimization for perovskite with a formula of FA0.7 MA 0.3Pb0.5 Sn0.5 I3 has been exercised by means of wet deposition. Different methods such as solvent engineering, changing precursor concentration and various deposition processes have been tested. Also, different additives have been used to suppress Sn oxidation in the device. The solar cell characteristics have improved up to 60%.
Perovskite photodetectors are a promising technology for imaging applications, due to their high performance, tunable absorption spectrum, and large area processability. New applications require devices with properties such as transparency, near-infrared (NIR) absorption, or scalability. Here, we have also fabricated semitransparent NIR perovskite photodetectors based on tin-lead (Sn-Pb) hybrid perovskites, by using very thin film perovskite layers (200 nm) and transparent indium tin oxide (ITO) electrodes. The top ITO contact was processed via pulsed layer deposition (PLD) with no damage to the underlying stack. The photodetectors have a full-stack transmission of over 48% in the NIR (between 780 and 1100 nm) and exhibit good performance with a dark current of 1.74·10-2 mA/cm2 (at -0.2 V), the external quantum efficiency of 23% and 13%, and detectivity of 6.6·1010 and 4.2·1010 Jones (at -0.2 V), at 850 and 940 nm, respectively. The performance of these devices makes them good candidates to be used as photodetectors for NIR applications or as bifacial devices.
We acknowledge support from the Comunitat Valenciana (PROMETEU/2020/077), the Spanish Ministry of Science and Innovation (MCIN) and the Spanish State Research Agency (AEI) for the project MAT2017-88821-R. Project RTI2018-095362-A-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. Project PCI2020-112084 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”. Grant RYC-2016-21316 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”. K.P.S.Z. acknowledges funding from Comunitat Valenciana (APOSTD/2021/368).