Research On Cesium Lead Halide Perovskite Microwires For Microlasers And Photon Detection

Microlasers have shown huge potential applications in the field of integrated optoelectronics as active devices.It can serve as the system light source,and form a practical function of on-chip photonic circuits with other integrated devices.Due to the excellent optical properties,all inorganic cesium perovskite becomes a new generation of semiconductor materials.The typical structure of cesium perovskite is microwire,which exists in the form of crystal.Under optical excitation,lasing action was observed from cesium perovskite microwire.Because of smooth facet and large optical gain,it forms a natural microlaser.However,the traditional preparation method is complex with too high cost.The prepared microwires have small cross-sectional sizes,which can only support the lower quality factor Fabry-Perot mode lasers.Because of poor quality,microwires applied to photon detection have shown low response time.In order to solve these problems,a one-step solution method was improved to prepare all inorganic cesium perovskite,and the laser properties and photon detection ability were studied.In order to meet the expectation,it has been proposed to prepare perovskite microwires with larger cross-sectional sizes.Based on the investigation of perovskite preparation methods,this paper has improved a one-step solution synthesis method,which successfully synthesized microwires with high quality,uniform shapes and large cross-sectional sizes.By femtosecond pulse laser excitation,the whispering gallery modes can be formed within the transverse planes of CsPbBr3 microwires for the first time.The highest quality factor can reach around 7000.The nonlinear effects of the microwires were studied by two-photon excitation.At the same time,the models of the tested samples were simulated and the correctness of the experimental results were confirmed.In theory,the stability of all inorganic perovskites is better than that of organic-inorganic hybrid perovskites.Based on this,the stability of the two lasers is studied under the femtosecond pulsed laser continuous pumping and high temperature heating.The results are consistent with the theory very well.In addition to the excellent laser properties of cesium bromide lead perovskite microwire,this paper also studied its photon detection performance.The gold film electrodes were prepared by vacuum electron beam evaporation and the three-dimensional transfer platform was constructed.The microwire was transferred to the gold film electrode by the adhesion of the tapered fiber.The change of the photo-generated current under different conditions was studied.The response times of microwires are around 8 ms,which are almost two orders of magnitude smaller than the previous report.Overall,based on the systematic study,cesium lead bromide perovskite microwires can pave new route to future development of integrated optoelectronic devices.