在Si衬底上异质外延GaAs薄膜变激发强度的近红外光致发光

Near-Infrared Photoluminescence with Different Excitation Intensity of Heteroepitaxial GaAs Layers Grown on Si Substrates

通过对用ＭＯＣＶＤ（金属有机物化学气相沉积）方法在Ｓｉ衬底上生长的ＧａＡｓ外延薄膜，用不同激发强度下的近红外光致发光研究了液氮温度下峰值能量为１．１３ｅＶ和１．０４ｅＶ两个带谱的发光特性，表明这两个带均属于施主－受主对复合发光。由于发光带中存在着电子－声子耦合，所以应在施主－受主对复合发光能量表示式中计及Ｆｒａｎｋ－Ｃｏｎｄｏｎ位移，从而对复合发光能量表示式进行修正。通过对复合发光带能量随激发强度变化的实验曲线和理论表达式的拟合，确定了峰值为１．１３ｅＶ与１．０４ｅＶ这两个发光带深施主－受主对的束缚能之和分别为０．３００ｅＶ和０．４０１ｅＶ。

With the heteroepitaxial GaAs layers grown on Si substrates,We have studied the excitation intensity dependence of the near- infrared photoluminescence (NIPL )related to the peak energy (77 K) at 1. 13 eV (A band) and 1.04 eV (B band) present in GaAs epitaxial layers grown by MOCVD.They can be explained by the recombination luminescence of the donor-acceptor pair.Taking the Frank-Condon shift into account,the energy expression with electron-lattice coupling effect is revised for deep donoracceptor pair. According to the experimental results,the sum of binding energies both Eaand Ed has been fitted,that is 0. 300 eV and 0. 401 eV,corresponding to A band and B band in NIPL spectra.