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Abstract Solution‐processed inorganic perovskites cause chemical and structural defects unfavorable for photodetector application. Using a binary solvent, defects in CsPbIxBry (CPIB) perovskite are passivated with poly 4‐vinylpyridine (PVP) and Poly methyl methacrylate (PMMA) polymers. X‐ray photoelectron spectroscopy and FTIR spectra reveal a Lewis base‐acid interaction between Pb2+ and polymer, confirming the passivation of CPIB perovskite. Scanning electron microscopy analysis shows a dual‐surface morphology with microribbons and microcrystals in perovskites. After PMMA treatment, CPIB perovskite exhibits a blue shift in the bandgap (1.8 to 1.95 eV), while the PVP induced a redshift, reducing the bandgap to 1.7 eV. Blue shift in PL analysis indicates modification of grain boundaries. A higher lifetime obtained for CPIB/PVP confirms the restraint of non‐radiative recombinations. Photodetectors are fabricated with pristine CPIB, CPIB/PVP, and CPIB/PMMA perovskites. The passivated CPIB/PVP‐based photodetector exhibits a quick rise time of ≈23 ms and a decay time of ≈17 ms. It also demonstrates a remarkable photoresponsivity of 23 mA W−1, an internal quantum efficiency of 4.9%, and a detectivity of 15.0 × 1010 Jones at 10 mW cm−2 light intensity. This approach shows the potential for environmentally stable polymers to passivate inorganic perovskites for high photodetection performance.

Abstract In present work, we report synthesis of nanocrystalline Kesterite copper zinc tin sulfide (CZTS) films by RF magnetron sputtering method. Influence of calcination temperature on structural, morphology, optical, and electrical properties has been investigated. Formation of CZTS has been confirmed by XPS, whereas formation of Kesterite-CZTS films has been confirmed by XRD, TEM, and Raman spectroscopy. It has been observed that crystallinity and average grain size increase with increase in calcination temperature and CZTS crystallites have preferred orientation in (112) direction. NC-AFM analysis revealed the formation of uniform, densely packed, and highly interconnected network of grains of CZTS over the large area. Furthermore, surface roughness of CZTS films increases with increase in calcination temperature. Optical bandgap estimated using UV–Visible spectroscopy decreases from 1.91 eV for as-deposited CZTS film to 1.59 eV for the film calcinated at 400 °C which is quite close to optimum value of bandgap for energy conversion in visible region. The photo response shows a significant improvement with increase in calcinations temperature. The employment these films in solar cells can improve the conversion efficiency by reducing recombination rate of photo-generated charge carriers due to larger grain size. However, further detail study is needed before its realization in the solar cells.