Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.287
Publication date: 20th April 2022
Halide perovskite indoor photovoltaics (PV) are promising to autonomously power the billions of sensors in the emerging technology field of the Internet of Things. However, there exists a knowledge gap in the hysteresis behavior of these photovoltaic devices under indoor lighting conditions. The present work is dedicated to exploring the degree of hysteresis in halide perovskite indoor photovoltaic devices as a function of device architecture and the selection of photoactive layers. Hysteresis properties were examined through both transient J–V scan and steady state maximum power point tracking (MPPT) measurements. It was observed that when MAPbI3 is used as the photoactive layer, compared to p-i-n device architecture consisting of all-organic charge transport layers, the n-i-p devices with metal oxide charge transport layers suffered higher hysteresis. And this hysteresis effect of n-i-p MAPbI3 devices got worse under the low intensity indoor illumination conditions. Our study revealed that the divergence between the PCE values estimated from the J–V scan measurements and the maximum power point tracking method was also higher under the indoor illumination compared to 1 Sun, necessitating the need to prioritize the PCE from the MPPT measurements over the conventional J–V scan measurements.
Light intensity measurement of photovoltaic parameters of these devices revealed that n-i-p devices suffer from higher trap-assisted recombination and poor charge extraction at interfaces than the p-i-n devices. The results from our study suggest the following approaches for maximising the steady-state PCE from halide perovskite indoor photovoltaics: (i) select perovskite active layer composition with suppressed ion migration effects (such as Cs-containing triple cation perovskites) (ii) for the perovskite composition such as MAPbI3, where the ion migration is very active, p-i-n architecture with organic charge transport layers is beneficial over the n-i-p architecture with conventional metal oxides (such as TiO2, SnO2) as charge transport layers.