以光照下耗尽型 ＡｌＧａＡｓ／ＧａＡｓ高电子迁移率晶体管为例，考虑了光生载流子对半导体内电荷密度的影响和光压效应，采用器件的电荷控制模型，分析了光照对器件夹断电压、二维电子气（２－ＤＥＧ）浓度、Ｉ—Ｖ特性以及跨导的影响．与无光照的情况相比较，夹断电压变小（绝对值变大），二维电子气浓度增大，从而提高了器件的电流增益．跨导对光照不敏感． Taking the depleted AlGaAs / GaAs high electron mobility transistor under light irradiation as an example, the influence of photocarriers on the charge density in semiconductor and the effect of photocousthe pressure were considered. The charge control model of the device was used to analyze the effect of illumination on the pinch- Two-dimensional electron gas (2-DEG) concentration, I-V characteristics, and transconductance. Compared with the case without illumination, the pinch-off voltage becomes smaller (the absolute value becomes larger), and the two-dimensional electron gas concentration increases, thereby increasing the current gain of the device. Transconductance is not sensitive to light.