日盲紫外硅/金刚石异质结光电二极管的结构设计和仿真

Structure Design and Simulation of Solar Blind Ultraviolet Silicon/Diamond Heterojunction Photodiode

金刚石作为新型宽禁带半导体材料具有成本低、无毒性和化学稳定性能好的优点,是紫外光电二极管的理想原材料之一,对代替目前普遍应用的含有稀有贵金属元素的紫外光电二极管有着积极的推动作用。在Silvaco软件Atlas模块上对日盲紫外硅/金刚石异质结光电二极管进行深入的分析,探讨其厚度、掺杂浓度与光电二极管暗电流、光谱响应、瞬态响应之间的关系,得到了光电二极管优化后的暗电流、反向击穿电压和掺杂浓度值。模拟仿真结果显示,该pin型硅/金刚石异质结光电二极管在10~220 nm范围内的响应灵敏度优于pn型器件,当器件波长为220 nm时,其响应电流最高达1.7×10^(-11)A,并且pin型硅/金刚石异质结光电二极管的暗电流比该pn型器件低,约为5.6×10^(-15)A。此模拟计算数据为进一步优化硅/金刚石光电二极管结构及实验制备奠定了理论基础。

Diamond is a semiconductor material with its low cost,nontoxic,and high chemical stability,which is also one of the ideal materials for ultra-violet photodiode.Its application in ultraviolet photodiode made it possible to replace the currently widely used ultraviolet photodiodes containing rare noble metal elements in the future.The device structure of solar blind ultraviolet silicon/diamond heterojunction photodiode was constructed by using Atlas module in Silvaco software.The effects of thickness and doping concentration on dark current,spectral response and transient response of photodiode were studied,and the dark current,reverse breakdown voltage and doping concentration of photodiode after preliminary optimization were obtained.The simulation results show that the silicon/diamond pin heterojunction photodiode has higher responsivity in the spectral range of 10—220 nm than that of the silicon/diamond pn heterojunction photodiode.When the peak wavelength is 220 nm,the maximum spectral response current of the photodiode is 1.7×10^(-11)A.The dark current of the pin heterojunction photodiode is approximately 5.6×10^(-15)A,which is smaller than that of the pn heterojunction photodiode.The work will lay a good foundation for the further structure optimization and the fabrication of high-performance silicon/diamond heterojunction photodiode.