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 widebandgap 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 (similar to 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 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.