Low-cost lead-free perovskite solar cell with graphene oxide as hole transport layer and carbon as back contact

Abstract

In this work, an innovative design for environmentally benign perovskite solar cells (PSCs) is introduced by incorporating graphene oxide (GO) as the hole transport layer (HTL) and utilizing carbon for the back contact. Eschewing the traditionally used CH3NH3PbI3, which raises environmental concerns due to lead content, the proposed design features the eco-friendly CH3NH3SnI3 as the absorber layer. The strategic inclusion of GO as the HTL amplifies the PSC's operational efficiency, owing to its superior exciton dissociation and charge transport properties, while simultaneously offering an economical fabrication strategy. Together with the carbon back contact, this configuration promises a sustainable and cost-efficient PSC solution. The proposed PSC architecture comprises FTO (window layer)/TiO2 (electron transport layer)/CH3NH3SnI3 (absorber layer)/GO (HTL)/C (back contact). Through rigorous optimization processes – encompassing parameters like layer thicknesses, interfacial defects, and doping levels – a commendable enhancement in PSC's performance metrics is achieved. The resultant design registered a power conversion efficiency (PCE) of 21.40% and a fill factor (FF) of 83.98%. Furthermore, thermal evaluation from 300 K to 400 K revealed the PSC's exceptional thermal resilience, underscoring its suitability for commercial deployment. All simulations and analyses are conducted using the SCAPS-1D software.