【摘要】 利用光电流谱法研究了300 K到60 K温度范围内的p-i-n结构4H-SiC紫外光电探测器的暗电流及相对光谱响应特性。研究发现随着温度的降低,探测器的暗电流和相对光谱响应都逐渐减小;而且,反向偏压越高,暗电流减小的速率越大。在零偏压下,随着温度的降低,器件的相对光谱响应的峰值波长先向短波方向移动,后向长波方向移动,在60 K时移至282 nm附近;同时观察到探测器的相对光谱响应范围略有缩小。此外,我们对器件p、i、n各层产生的光电流随温度变化的机理进行讨论,提出了通过减少i层缺陷和适当减小n层掺杂浓度的方式来提高器件的相对光谱响应。更多还原

【Abstract】 The dark current and relative spectral response of 4H-SiC ultraviolet p-i-n photodetector were investigated with the temperature decreasing from 300 K to 60 K by photocurrent measurement.It is found that the dark current and relative spectral response of the device declined during the whole period and that the higher the reverse bias voltage is,the faster the falling rate of dark current are.At the reverse bias of 0 V,when the temperature dropped,the peak response wavelength of the device firstly shifted slowly to the short wavelength direction and then moved to the opposite direction,reaching around 282 nm at 60 K. Meanwhile,a littie narrowing of relative spectral response of the device was observed.Furthermore,the mechanism of influences of temperature on photocurrent produced in p,i,n layers were investigated,and proposal lessening defect in i layer and reducing properly doping concentration in n layer were proposed to enhance the relative spectral response of the device.更多还原