2021 Adv. Funct. Mater.: Exceed 21% efficiency! Rebuild The Photosensitive Layer of All-inorganic Perovskite/Organic Solar Cells

　　Advanced Functional Materials (IF 18.808) published a study on all-inorganic perovskite/organic tandem solar cells in October 2021. Researchers used the complementary characteristics of the photosensitive layer to reconstruct the surface for achieving stability and high efficiency.

　　By overcoming the Shockley-Queisser limit of single-junction solar cells, the construction of monolithic two-terminal tandem solar cells (2T TSCs) provides the possibility of high power conversion efficiency (PCE). However, few people have noticed that the complementary characteristics of various photosensitive layers can be utilized while improving stability. In this study, the researchers used trimethylammonium chloride to reconstruct the surface of the all-inorganic perovskite. By doing this, researchers improve the charge recombination efficiency in the interconnection layer (ICL) between the sub-cells and realize the all-inorganic perovskite (CsPbI_1.8Br_1.2) monolithic integration. The repaired CsPbI_1.8Br_1.2 surface can effectively inhibit non-radiative recombination and promote hole transport, thereby providing effective charge recombination in the interconnecting layer (ICL) of 2T TSC.

　　The researchers used Enlitech’s Solar Simulator and QE-R quantum efficiency measurement system to measure the spectral response. The research results showed that the all-inorganic perovskite/organic 2T TSC reached a power conversion efficiency (PCE) of 21.04%. And accompanied by an ultra-high open circuit voltage (V_oc) of 2.05 V. In addition to the EQE (External Quantum Efficiency) spectrum analysis of solar cells, the Quantum Efficiency Measurement System of Enlitech also provides Jsc (short-circuit current density) comparison for the short-circuit current of solar cells under the solar simulator and prove the authenticity of the experiment. The solar simulator and KA-6000 software of Enlitech also provide monitoring of the short-circuit current over time to prove the stability of the solar cell!