【作者】 陈进；

【导师】 苟君；

【作者基本信息】 电子科技大学 ， 电子信息（专业学位）， 2023， 硕士

【摘要】 硅基光电探测器制备工艺成熟,光电性能优良,广泛应用于国防、工业和民用等多个领域,但传统的硅基光电探测器可探测波长范围有限,对近红外光的光电响应较弱。集成限光结构可以增强器件的光吸收率,借助其他窄带隙半导体材料能有效拓宽响应波段。硒化铅(Lead Selenide,PbSe)是一种常见的Ⅳ-Ⅵ族化合物,常温常压下块体材料禁带宽度为0.28 e V,是用于红外光电探测的理想半导体材料。本文基于PbSe材料,制备并研究了集成限光结构的硅基PbSe薄膜及量子点光电探测器。通过有限时域差分法(Finite Difference Time Domain,FDTD)仿真软件对集成限光结构的器件进行光学仿真,探究了微孔直径、周期以及衬底等变量对微孔结构限光效果的影响,计算分析了器件光吸收率和电场强度分布,仿真结果表明,微孔结构限光能力与微孔尺寸紧密相关,当微孔直径/周期为700/1000 nm时器件光吸收率最高,光电性能最优。同时通过有限元漂移-扩散法仿真软件Lumerical CHARGE(简称CHARGE)仿真了工作电压及电极间距对器件内电场分布的影响,仿真结果表明,增大工作电压和减小电极间距可以加深电场深度。基于真空蒸镀法制备了致密均匀的PbSe薄膜,薄膜表面粗糙度低且结晶颗粒小。通过光刻、刻蚀和溅射等半导体工艺在薄膜表面制备了微孔结构和叉指电极。器件可探测405～1550 nm波段入射光,有效拓宽硅基探测器的截止波长,同时限光结构显著提升了器件光电性能。器件在1550 nm处响应度最高为0.285 A/W,比探测率为4.195×10~9Jones,响应时间最小为48.49μs。基于热注入法制备了性质稳定的PbSe量子点,表征测得量子点直径约为6.28nm,第一激子吸收峰位于1732 nm处,计算得到量子点带隙约为0.695 e V。将PbSe量子点溶液旋涂在具有限光结构的器件表面,测试表明器件具有宽光谱响应特性,量子点给器件内部带来增益,微孔结构也提高了器件的光电响应度。器件在1550nm处响应度最高为1.93 A/W,比探测率为2.227×10~9Jones,在850 nm波长处的响应时间为8.67μs。更多还原

【Abstract】 Silicon-based photodetectors,with mature preparation technology and excellent photoelectric performance,are widely used in national defense,industry and civil and other fields.However,traditional silicon-based photodetectors have limited detection wavelength range and weak photoelectric response to near-infrared light.Therefore,The integrated light limiting structure can enhance the light absorption of the device,and broaden the response band by combining with other narrow band gap semiconductor materials.Lead Selenide(PbSe)is a common compound of groupⅣ-Ⅵ,and the band gap of bulk materials is 0.28 e V at normal temperature and pressure,which is an ideal semiconductor material used for infrared photoelectric detection.Based on PbSe material,silicon-based PbSe thin film and quantum dot photodetectors with integrated light-limiting structure were prepared and researched in this thesis.The optical simulation of the devices with integrated light-limiting structure is carried out through the finite difference time domain(FDTD)simulation software,The influences of micropore diameter,period and substrate on the light limiting effect of micropore structure were investigated,the light absorption rate and electric field intensity distribution of the device were calculated and analyzed.The simulation results show that the light-trapping ability of the micropore structure is closely related to the micropore size,when the micropore diameter/period is 700/1000 nm,the light absorption rate of the device is the highest and the photoelectric performance is the best.Moreover,the influence of the working voltage and electrode spacing on the electric field distribution in the device was simulated by the finite element drift-diffusion simulation software Lumerical CHARGE(CHARGE).The simulation results show that increasing the working voltage and decreasing the electrode spacing can deepen the electric field depth.PbSe thin films were prepared by vacuum evaporation method with low surface roughness and small crystal particles.The microporous structures and interfinger electrodes were prepared on the surface of the thin films by semiconductor processes such as photolithography,etching and sputtering.The device can detect the incident light at405～1550 nm band,The cutoff wavelength of the silicon-based detector is broadened effectively,and the optical limiting structure significantly improves the photoelectric performance of the device.The device has a maximum responsitivity of 0.285 A/W at1550 nm,a specific detectivity of 4.195×10~9Jones,and a minimum response time of48.49μs.PbSe quantum dots with stable properties were prepared by thermal injection method,the diameter of the dots is about 6.28 nm,and the first exciton absorption peak is at 1732nm,and the calculated band gap of the dots is about 0.695 e V.Then,PbSe quantum dot solution was spun on the surface of the device with light-trapping structure.Test shows that the device has wide spectral response characteristics,the quantum dot brings gain to the inside of the device,and the microporous structure improves the photoelectric responsitivity of the device.At 1550 nm,the device has a maximum responsitivity of 1.93A/W,a specific detectivity of 2.227×10~9Jones,the response time at 850 nm wavelength is 8.67μs.更多还原