Synthesis and DFT calculation of germanium halide perovskites with high luminescent stability, and their applications in WLEDs and indoor photovoltaics

Addressing environmental pollution by entirely substituting lead is a significant concern in the field of perovskite optoelectronic devices. In this study, we used density functional theory to predict the structure and properties of the lead-free compound CsGeBr3, followed by its successful experimental synthesis. CsGeBr3 demonstrated the capability to emit white light and exhibited notable stability under UV radiation. Moreover, when combined with red-emitting MOF:Eu3+ phosphors, CsGeBr3 was effectively used to fabricate white light-emitting diode (WLED) devices. These devices exhibited a commendable color rendering index (CRI) of 92 and a correlated color temperature (CCT) of 3020 K. Furthermore, these light-emitting diode (LED) devices demonstrated their capacity to efficiently stimulate silicon solar cells, resulting in impressive photoelectric performance. We observed an increase in the open-circuit voltage, short-circuit current density, and cell impedance as the LED operating voltage increased, while the fill factor remained relatively unchanged. Given these beneficial properties, we strongly believe that lead-free CsGeBr3 holds promising potential for further research and development in the fields of WLEDs and indoor photovoltaics.

Automated summary

Addressing environmental pollution by replacing lead in perovskite optoelectronic devices is a major concern. This study used density functional theory to predict the properties of lead-free compound CsGeBr3 and successfully synthesized it. CsGeBr3 showed the ability to emit white light and demonstrated stability under UV radiation. By combining CsGeBr3 with MOF:Eu3+ phosphors, white light-emitting diode (WLED) devices with commendable color rendering index (CRI) and correlated color temperature (CCT) were fabricated. These WLED devices also efficiently stimulated silicon solar cells, resulting in impressive photoelectric performance.