GaNAs/GaAs量子阱的静压光致发光研究

Investigation of Photoluminescence from GaNAs/GaAs Quantum Well under Hydrostatic Pressure

在 1 5 K和 0～ 9GPa静压范围下测量了 Ga N0 .0 1 5As0 .985/ Ga As量子阱的光致发光谱。观察到了 Ga NAs阱和 Ga As垒的发光 ,发现 Ga NAs阱发光峰随压力的变化比 Ga As垒发光峰要小很多。当压力超过 2 .5 GPa后还观察到了与 Ga As中的 N等电子陷阱有关的一组新发光峰。用二能级模型及测得的 Ga As带边和 N等电子能级的压力行为计算了 Ga NAs发光峰随压力的变化 ,但计算结果与实验结果相差甚大 ,表明二能级模型并不完全适用。对观察到的 Ga NAs发光峰的强度和半宽随压力的变化也进行了简短讨论。

The photoluminescence of GaN 0.015 As 0.985 /GaAs quantum well has been measured at 15 K in the pressure range from 0 to 9 GPa.Both the emissions from the GaNAs well and the GaAs barrier are observed.But the GaNAs related peak shows a much weaker pressure dependence comparing to that of GaAs band gap.A group of new peaks appears in spectra when pressure is increased beyond 2.5 GPa,which is attributed to the emissions from the excitons bound to the N isoelectronic traps in GaAs.The pressure dependence of GaNAs related peaks was calculated using the two level model and the measured pressure coefficients of GaAs band gap and N level,but the calculated results deviate largely with the experimental data.It seems that the simple two level model cannot explain the pressure behavior of GaNAs alloy very well.The pressure dependence of the emission intensity and the line width for the GaNAs related peaks was also discussed briefly.