区熔单晶硅与直拉单晶硅以及其他半导体材料相比杂质含量少 ,少子寿命长 ,所以以区熔单晶硅为衬底制作的光晶体管在弱的光信号下仍然有高的增益 ,适宜于弱光探测 报道了以区熔单晶硅为衬底的光晶体管的实验结果 为了保持区熔高纯单晶硅内的少子寿命 ,背面淀积了一层掺磷多晶硅作为外吸杂层 已经测量得到对于实验中发射极直径为 2mm的光晶体管在波长为0 .83μm的入射光照射下 ,光功率低至 0 .16nW时 ,光晶体管的增益仍然高达 4 40 0 Compared with Czochralski (CZT) and other semiconductor materials, the melting point of single crystal silicon is less than that of other semiconductor materials, and the lifetime of the minority carriers is long. Therefore, the phototransistor fabricated from the single crystal silicon with the region melting still has a high gain under a weak optical signal , Suitable for weak light detection Experimental results of phototransistors with zone-melting monocrystalline silicon substrate. In order to maintain a low minority lifetime in the zone-fused high purity single crystal silicon, a layer of phosphorus-doped polycrystalline silicon is deposited on the back side as extra- Layer has been measured for the experimental emitter diameter of 2mm phototransistor at a wavelength of 0.83μm incident light irradiation, the optical power down to 0.16nW, the phototransistor gain is still as high as 4 40 0