Design and simulation investigations on electron transport layer-free in tin-based p-n homojunction perovskite solar cells

Abstract

Inverted tin-based perovskite solar cell (PSC) devices with the electron transport layer-free (ETL-free) have drawn tremendous attention. Nonetheless, the photovoltaic performance of the device still lags behind that of conventional structural devices. In this context, a novel ETL-free inverted PSC with p-type MASnI3/n-type MASnI3 all-perovskite homojunction as light-harvester has been modeled and investigated by using wxAMPS software. This innovative PSC configuration not only promotes carrier separation and oriented transmission but also reduces carrier recombination losses. The simulation results reveal that NiO stands out as the best alternative. To enhance the device's overall efficiency, the optimal hole transport layer and perovskite layer thickness should be 30 nm and 200 nm, respectively. Lower defect densities in the perovskite layer and interface layers can favor the reduction of carrier recombination losses and efficient carrier transfer. Additionally, superior-performance photovoltaic devices can be further realized with a moderate perovskite layer acceptor doping density of 1E14 cm−3. With these optimized values, the optimal power conversion efficiency (PCE) of 20.5609 % has been obtained for the PSC devices. This work indicates that the proposed inverted homojunction PSC with ETL-free will be a valuable reference for future research in optoelectronic and electro-optical devices.