Minimized surface deficiency on wide-bandgap perovskite for efficient indoor photovoltaics

Wide-bandgap perovskite solar cells (PVSCs) possess significant potential in providing reliable power sources for applications in the Internet of Things (IoT) ecosystem under indoor light illumination. However, the wide-bandgap PVSCs usually suffer from photo-induced phase segregation and non-radiative energy loss caused by the Shockley-Read-Hall (SRH) type trap-assisted recombination at the interfaces in the devices. To address these issues, a simple strategy by applying phenethylammonium halides to reduce the energy loss and suppress the phase segregation of wide-bandgap PVSCs is developed. The devices incorporated with phenethylammonium chloride (PEACl) is revealed to achieve a high open-circuit voltage (V_OC) of 1.26 V, leading to a merit power conversion efficiency (PCE) of 18.3%, which is the best performance among the inverted wide-bandgap PVSCs (~1.75 eV) under one sun illumination. Meanwhile, the photovoltaic performance of the device is also significantly enhanced, especially under a white light-emitting diode (LED) with an illumination of 1000 lux, showing a PCE of 35.6% with a high V_OC of 1.08 V. Impressively, the device delivers a minimum energy loss of 670 meV, which is among the smallest value reported for perovskite-based indoor photovoltaics.