Design and Simulation of a‐Si:H/PbS Colloidal Quantum Dots Monolithic Tandem Solar Cell for 12% Efficiency

Abstract

Tandem solar cells (TSC) is the most promising photovoltaic technology, as it efficiently overcomes the thermalization and nonabsorption losses. In this context, thin-film/colloidal quantum dot (CQD)-based 2-terminal monolithic TSCs are designed using a-Si:H of wide bandgap (1.7 eV) as the top cell and PbS CQD of narrow bandgap (1.2 eV) as the bottom cell. Initially, top and bottom subcells are designed and calibrated to have state-of-the-art power conversion efficiencies (PCE) of 6.86% and 9.38%, respectively. Afterward, the thicknesses of the inverted bottom cell are optimized as 200 nm so as to obtain 8.34% efficiency. The standalone condition reflects current density (J SC)/open-circuit voltage (V OC) of 9.97 mA cm À2 and 0.91 V in the top cell and 21.28 mA cm À2 / 0.63 V in the bottom cell. Further, both subcells are evaluated for tandem configuration with ITO-based interlayer to provide the current matching conditions. In the proposed tandem design, the thickness of the absorber layers is optimized to achieve the highest J SC , which is indeed limited by the top cell, due to a lower J SC value of 10.61 mA cm À2 in standalone conditions. Optimized tandem design with 200 nm/150 nm-thick absorber layer-based top/bottom subcell results in

The impact of chemical composition of halide surface ligands on the electronic structure and stability of lead sulfide quantum dot materials

“…The bandgap engineering can be useful in multi-junction solar cell devices, which have a potential to achieve power conversion efficiencies that go beyond current commercial solar cells. 18,19 Currently, among the single junction PbS QD solar cells, the highest power conversion efficiencies (above 13%) are achieved using a thin film of PbS QDs with I − and Br − surface ligands as the main absorbing material. These quantum dots have a bandgap of 1.3 eV, achieved by a particle size of approximately 3–4 nm in diameter.…”

Status and challenges of multi-junction solar cell technology

“…Both QDs and organic materials possess additional fabrication advantage of liquid-phase deposition of thin films via, spin-coating, spray-drying or printing (Lin et al, 2021). Due to easy non-vacuum fabrication, QDs and organic solar cell layers can be integrated with other photovoltaic technologies, for example amorphous Si cell reaching efficiencies of >12% for PbS/Si (Kashyap et al, 2020) and 11.7% for organic/Si (Roland et al, 2015) tandem cells.…”

Investigations aimed at producing 33% efficient perovskite–silicon tandem solar cells through device simulations

“…We understand the need for TRJ in monolithic tandem solar cells and investigated tandem devices in the past with physical TRJ. [36][37][38][39] However, the ongoing work is carried out using the SCAPS-1D simulator, which does not support the TRJ layer and only supports a maximum of seven semiconducting layers. Therefore, the ltered spectrum followed by the current matching technique is utilized to design and investigate the PVK-Si monolithic tandem solar cell.…”