CH3NH3PbBr3 quantum dots for visible wavelength photodetector applications
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Perovskite halide materials with their salient optoelectronic features such as high absorption coefficient, large charge carrier diffusion lengths and low carrier recombination, have revolutionised the field of photodetectors. In this paper we report the synthesis of CH3NH3PbBr3 quantum dots for visible wavelength photodetector applications. Quantum dots of size 2–4.5 nm were obtained. UV–Vis and photoluminescence spectroscopy revealed an optical band gap of 2.3 eV. An electrochemical band gap of 2.09 eV was obtained using cyclic voltammetry. CH3NH3PbBr3 quantum dots based visible wavelength photodetector device was fabricated. The time dependent photoresponse was found to be stable over several ON–OFF cycles of the lamp. We have achieved a responsivity, external quantum efficiency and specific detectivity of 6.11 A W−1, 1380.2% and 3.81 × 1012 Jones under AM 1.5 G, 1 sun illumination.
The authors would like to thank Ms. Ramya from Prof. Aveek Bid’s group (Physics Dept., IISc) for helping in the noise measurements. Also we would like to thank Mr. Debanjan Das from Prof. K.K. Nanda’s group (Materials Research Centre, IISc) for helping in the cyclic voltammetry measurements. The author Dr. Sandra Dias would like to thank the IISc Research Associate fellowship.