摘要
测量了垂直于结平面各空间位置的荧光光谱和某些特定波长的空间分布.实验结果表明在 n-GaAs衬底、n-GaAs缓冲层和 P-GaAs有源层都存在着峰值波长为 1.03 μm和 1.09μm的深能级辐射.这些辐射在热处理和小电流密度老化下有着不同的行为. 另外在N-Ga_(1-x)Al_xAs层的荧光谱中还可以看到一个波长比有源区带到带的辐射还短的辐射.可以认为这是由于在N-P异质界面存在着电子势垒从而导致在N-Ga(1-x)AlxAs层中导带的非平衡电子与在Sn深受主能级上的非平衡空穴复合产生的辐射.
The luminescence spectra at various spatial position perpendicular to the junctionplane of a DH laser has been studied.For certain wavelength the spatial distributionof the luminescence was also investigated.The experimantal results show that the deeplevel radiation peaks at wavelenghth of 1.03 μ and 1.09μ (called as D_1and D_2) appearedthroughout the region of N-GaAs substrate,N-GaAs buffer layar and P-GaAs activelayer. The intensity of those peaks became maximum in the buffer layer nearby theactive region about 3-6 μm away from the N-n heterojunction. Under enhanced agingwith lower current density (heat sink temperature 70℃, current density 500A/cm^2)the intensity of the two radiation peaks slightly increased and the position of the ma-ximum moves toward N-n heterojunction, but after thermal treatment at 800℃ theintensity of the two peaks evidently decreased.Besides it was discovered that there wasalso a deep level radiation peak at wavelength of about 1.03 μ in the P-GaAs activeregion (D_1'). This radiation peak, however, would not be effected by the thermal treat-ment, and during enhenced aging with lower current density the intensity of it signifi-cantly reduced, which agrees with fact that the threshold current density decreases inthe early period of the aging process. It was also found that the luminescence spectrum ofN-Ga_(1-x)Al_xAs layer has a radiation peak, whose wavelength is shorter than that of theband to band transition in the active region.It can be considered that this radiationpeak results from the recombination of the holes bound by Sn deep acceptor with theelectrons,which appeared in N-Ga_(1-x)Al_xAs layer due to the existence of the potentialbarriers in the conduction band at N-p heterojunctions.
