The Fabrication of Perovskite/Cztse Tandem Solar Cells

This project is to fabricate a low-cost, high-efficiency monolithic perovskite/copper-zinc-tin-selenide tandem solar cell. When the efficiency of single-junction solar cells is facing a serious bottleneck, multi-junction tandem solar cells provide an effective way to increase efficiency owing to that more spectra can be absorbed. It is well known that to make a high-efficiency tandem cell, we must first reduce the shading effect and then allow more light to enter the bottom cell by selecting the appropriate absorption energy gap, interface layer and electrode. Anti-reflection layer, surface texturing and light-trapping techniques can be used to reduce light reflection. The series resistance in tandem cells can be minimized by using a suitable transparent conductive layer. It is expected to complete the research and production of low-cost, high-efficiency perovskite/copper-zinc-tin-selenium tandem solar cells in two years. The first year's research focuses on optimizing the fabricating parameters of perovskite layer by using 1. Incorporation of Nafion and organic solvents into the PEDOT:PSS solution for improving the properties of the PEDOT:PSS film; 2. To study the bandgap variation of FAxMA1-xPb(I1-yBry)3 and MAPb(I1-xBrx)3 perovskites with different Br ratios. Selecting proper bandgap reaches the best energy gap match in tandem solar cells. The transmittance and its efficiency value are explored and the thickness of the absorber layer is adjusted to complete the current matching of the upper and lower tandem cells; 3. The concentration of the perovskite precursor, the type of the rinse solvent and thermal annealing temperature are investigated optimize the properties of the perovskite films. 4. Appropriate solvent annealing and the use of mixed PCBM molecules and C60-DPM-OE molecules to improve perovskite/ETL interface quality. The second year of research focuses on optimizing the tunnel layer and transparent conductive layer by using: 1. Study and compare the effect of using NiO, SnO2 and ITO as the tunnel layer on the performance of the tandem solar cell; 2. Study and compare the use of ITO, SnO2, silver nanowires or graphene as transparent conductive layer; 3. Focus on the stability problems of perovskite by using the incorporation of Cs and Rb in the FAxMA1-xPb (I1-yBry)3 perovskite to increase the stability. The fabricating parameters in tandem solar cells were optimized to achieve higher efficiency.

Project ID:PB10907-4033
External Project ID:MOST109-2221-E182-003-MY2