Controllable Growth Of Low-dimensional Semiconductors For Broadband Photodetection

Due to the unique physical and chemical properties,low-dimensional semiconductors have attracted extensive attention in electronics,optoelectronics,mechanics,sensors and so on.With the development of nanotechnology and the requirement of the semiconductor industry,there are many problems in the theoretical screening of materials,controllable growth and the physical properties of quantum dimensions of low-dimensional materials.Besides,low-dimensional semiconductors used as channel materials of photodetection need to have suitable band gap,high-quality crystal structures,controllable sizes and morphologies.Broadband detection is also one of the requirements for the development of modern photodetection technology.In this paper,the solid-source chemical vapor deposition(CVD)method is used to growth the all-inorganic perovskite precursors PbI2 nanobelts,lead-free all-inorganic CsSnX3 perovskite nanowire arrays and full-composition-range GaAs1-xSbx nanowires.Furthermore,the performance of photodetectors with a detection range from visible to infrared light is also studied.The main contents can be summarized as follows:1.Controllable growth and the photodetection performance of large-size,high-quality PbI2 nanobelts.A simple and easy-to-use solid-source CVD method is used to controllable growth PbI2 nanobelts with large-size(length>100 ?m),high-quality crystal structure by the two-step self-catalyzed method.The as-prepared large-size PbI2 nanobelts with a bandgap of 2.36 eV and exhibits good detection performance for visible light:a low dark current of 4 pA,an impressive ON/OFF ratio of 103-104,a photoresponsivity of 13 mA·W-1,and a response with the rise and decay time of 425 ms and 41 ms.All the results show that the as-prepared large-sized,high-quality Pbl2 nanobelts have great application potential in the next-generation of high-performance photodetector devices.Related results have been published in Journal of Materials Chemistry C,2018,6,5746.2.Controllable growth and the near-infrared photodetection performance of lead-free all-inorganic perovskite nanowire array.Using solid-source CVD method to controllable growth lead-free all-inorganic CsSnX3(X=Cl,Br and I)perovskite nanowire array.On the one hand,the toxicity of the Pb element is avoided;on the other hand,the band gap of the existing perovskite semiconductors is reduced to the near infrared.The band gaps of the as-prepared CsSnX3 perovskite nanowire arrays decrease from 1.84 to 1.34 eV with X changes from Br to I.The as-prepared high-quality CsSnI3 perovskite nanowire array is fabricated into a near-infrared photodetector for the first time,exhibits good detection performance:a high detectivity of 3.85 ×105 Jones,a responsivity of 54 mA·W-1,and rise and decay time of 83.8 ms and 243.4 ms.All the results show that the prepared lead-free all-inorganic CsSnX3 perovskite nanowire array has huge application potential in the next-generation of high-performance photodetectors.Related results have been published in The Journal of Physical Chemistry C,2019,123,17566.3.Controllable growth of full-composition-range GaAs1-xSbx nanowires and the near-infrared photodetection property.Based on narrow band gap ?-? semiconductors,broadband infrared detection can be achieved through bandgap engineering.In this part,a simple and low-cost surfactant-assisted solid-source CVD method can be used to controllable growth of high-quality full-composition-range GaAs1-xSbx nanowires,showing excellent detection performance for 1310 nm infrared light:a high detectivity of 5.6 × 108 Jones,a high responsivity of 616.4 A·W-1 and fast rise and decay time of 2.4 ms and 6.3 ms.In conclusion,the results of this study will provide theoretical and technical support for the design and performance improvement of channel materials for broadband photodetectors.Related results are being collated and pending publication.