本文报道ＧａＡｓ／ＡｌＧａＡｓ多量子阱长波长红外探测器材料的制备及其性能．这种材料由ＧａＡｓ阱和ＡｌＧａＡｓ势垒组成，除内ｎ型掺杂，具有５０个周期．利用分子束外延技术成功地生长出了大面积（２英寸）均匀（厚度△ｔ＿ｍａｘ／≤３％，组分△　ｘ＿ｍａｘ／ｘ≤３．４％，掺杂浓度△ｎｍａｘ／ｎ≤３％，椭圆缺陷≤３００ｃｍ－２）的外延材料．分析了暗电流的成因，通过加厚势垒（Ｌｂ≥３００）、控制掺杂（ｎ≤１×１０￣１８ｃｍ￣３）、精确设计子带结构，将暗电流降低了几个数量级，同时使电子的输运得到了改善．由此得到了高质量的多量子阶红外探测器材料． This paper reports the preparation and properties of GaAs / AlGaAs multi-quantum well long wavelength infrared detectors. This material consists of a GaAs well and an AlGaAs barrier with 50 periods except n-type doping. A large area (2 inches) of uniform thickness (Δt_max / ≤3%, Δx_max / x≤3.4%, doping concentration △ nmax / n≤3%) was successfully grown by molecular beam epitaxy Defects ≤ 300cm-2) of the epitaxial material. The causes of the dark current are analyzed. By thickening the barrier (Lb≥300) and controlling the doping (n≤1 × 10 ~ 18cm ~ 3), the sub-band structure is precisely designed to reduce the dark current by several orders of magnitude, The transport of electrons has been improved. As a result, a high quality multi-quantum infrared detector material was obtained.