Non-ultrawide bandgap CsPbBr_(3) nanosheet for sensitive deep ultraviolet photodetection

摘要

In this study,we report the fabrication of a sensitive deep ultraviolet(DUV)photodetector by using CsPbBr_(3) nanosheets synthesized through confined-space growth at room temperature.The peak pho-toresponse of the device upon illumination blueshifts with decreasing thickness and a 68 nm CsPbBr_(3) nanosheet based device displays a peak response to 265 nm illumination,showing responsivity and spe-cific detectivity of 85 mA/W and 4.05×1011 Jones at 3 V bias,respectively.Theoretical simulation re-veals that the blueshift is associated with the wavelength-dependent absorption coefficient of CsPbBr_(3) nanosheet:incident light with shorter wavelengths can be absorbed on the superficial surface,while long-wavelength light has a larger penetration depth,leading to dominant DUV absorption in thinner CsPbBr_(3) nanosheet.This work will shed light on the facile and cost-effective fabrication of DUV photode-tectors from non-ultrawide bandgap(UWBG)all-inorganic perovskite materials.