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利用低能双离子束外延技术 ,在 4 0 0℃条件下生长样品 (Ga,Mn,As) / Ga As.样品光致发光谱出现三个峰 ,即1.5 0 4 2 e V处的 Ga As激子峰、1.4 875 e V处的弱碳峰和低能侧的一宽发光带 .宽发光带的中心位置在 1.35 e V附近 ,半宽约 0 .1e V.在 84 0℃条件下对样品进行退火处理 ,退火后的谱结构类似退火前 ,但激子峰和碳杂质峰的峰位分别移至 1.5 0 6 5 e V和 1.4 894 e V,同时低能侧的宽发光带的强度大大增加 .这一宽发射带的来源还不清楚 ,原因可能是体内杂质和缺陷形成杂质带 ,生成 Mn2 As新相 ,Mn占 Ga位或形成 Ga Mn As合金
The sample (Ga, Mn, As) / GaAs was grown by low energy double ion beam epitaxy at 400 ℃. There were three peaks in the photoluminescence spectrum Sub-peak, a weak carbon peak at 1.4 875 e V, and a broad band at the low-energy side. The center of the broad band is near 1.35 eV with a half-width of about 0.1eV. Samples are taken at 84 0 ° C After annealing, the spectra were similar to those before annealing, but the peak positions of excitons and carbon impurities shifted to 1.5 0 6 5 e V and 1.4 894 e V, respectively, and the intensity of the broad emission band on the low energy side increased greatly. The origin of this broad emission band is unclear, probably due to the formation of impurity bands in the impurities and defects in the body resulting in the formation of a new phase of Mn2As with Mn accounting for Ga sites or forming a GaMnAs alloy