高灵敏度穿通型异质结光电晶体管

报导了一种带有独特隔离环结构的宽禁带发射区平面穿通型光电晶体管（ＧＲ－ＰＴＨＰＴ），在弱光信号下具有高灵敏度。器件工作时基区全部耗尽，基极电流基本为零，输出噪声电流大大下降，使光电增益提高了一个量级以上。已研制成的ＧａＡｌＡｓ／ＧａＡｓ穿通型光电晶体管（发射极直径φ＝４μｍ）。在５Ｖ工作电压下，对０．８μｍ，１．３ｎｗ和４３ｎｗ弱光的光电增益分别为１２６０和８１０８。折合到输入端暗电流为０．８３ｎＡ。

High Sensitivity Punchthrough Heterojunction Phototransistors

The planar punchthrough heterojunction phototransistors with a novel emitter guard-ring(GR-PTHPT) are researched. The phototransistors have high sensitivity at low input power. The base of transistor is completely depleted under the operating condition. Base current is zero. The output noise current is reduced.The GaAlAs/GaAs punchthrough phototransistors (emitter diameter φ=4 μm) are fabricated. The trasistors exhibit optical gain as high as 1 260 and 8 108 at incident optical power as low as 1. 3 nW and 43 nW, respectively. The reduced input dark current is 0. 83 nA.