本文分析了常规扩散方法形成的Pn结普通硅光电二极管,光谱响应偏于可见光的长波及近红外区,针对短波响应差的原因提出了表面反型结构的器件设计.实验表明,光谱响应曲线(等能)比较接近人的视见函数,响应峰值移到了5400,在4000时相对灵敏度约70%左右,长波限移到8600～9000范围. In this paper, the common Pn junction silicon photodiode formed by the conventional diffusion method is analyzed. The spectral response is in the long wave and near infrared region of visible light, and the device design of the surface inversion structure is proposed for the reason of the short wave response difference.Experiments show that the spectral response curve Equal energy) is closer to the human visual function, the response peak shifted to 5400 , at 4000  relative sensitivity of about 70%, long-wave limit to 8600 ~ 9000  range.