Performance analysis of wide bandgap inorganic perovskite for indoor photovoltaics for IoT applications: simulation study

Indoor Photovoltaics are designed to harness indoor light energy for direct electricity generation. Their availability and ambient energy harvesting potential make them an attractive solution for powering electronics in the Internet of Things (IoT) ecosystem. Pb-free, ambient stable, inorganic perovskite CsGeI3 with a wide bandgap of 1.8 eV is computationally analysed for indoor photovoltaic application. It showed a photovoltaic efficiency of 58% in indoor light emitted diode illumination and 55.7% in compact fluorescent light illumination. The narrow emission spectrum of indoor light sources allows better coverage of the spectrum by a wide bandgap absorber, which lowers thermalization losses and thus reaches higher power conversion efficiency. Indoor photovoltaic (IPV) has different device optimization strategies than outdoor 1 sun illumination optimized devices. The main difference is low photogenerated carrier density due to lower incident photons in dim light, which increases the ratio of trapped electrons to photogenerated electrons. This makes the IPV device more susceptible to shunt resistance and interfacial recombination. The series resistance does not impact IPV device efficiency. The high efficiency demonstrated here paves the way for inorganic wide-bandgap perovskite solar cells to play a significant role in powering indoor electronics for the IoT.