中文摘要：

利用分子束外延方法制备了应用于四结光伏电池的1.05 eV InGaAsP薄膜,并对其超快光学特性进行了研究.温度和激发功率有关的发光特性表明：InGaAsP材料以自由激子发光为主.室温下InGaAsP材料的载流子发光弛豫时间达到10.4 ns,且随激发功率增大而增大.发光弛豫时间随温度升高呈现S形变化,在低于50 K时随温度升高而增大,在50-150 K之间时减小,而温度高于150 K时再次增大.基于载流子弛豫动力学,分析并解释了温度及非辐射复合中心浓度对样品材料载流子发光弛豫时间S形变化的影响.

英文摘要：

The photoluminescence properties of InGaAsP films with a bandgap energy of 1.05 eV for quadruple-junction solar cells grown by molecular beam epitaxy （MBE） are investigated. We make the excitation intensity and temperature dependence of continuous-wave photoluminescence （cw-PL） measurements. The PL peak position is 1.1 eV at 10 K, and almost independent of the excitation power, but the integrated intensity of the PL emission peaks is roughly proportional to the excitation power. The shift of peak position with temperature follows the band gap shrinking predicted by the well-known Varshni’s empirical formula. These results indicate that the intrinsic transition dominates the light emission of the InGaAsP material. In addition, we also make the time-resolved photoluminescence （TRPL） measurements to determine the carrier luminescence relaxation time in InGaAsP. PL spectra suggest that the relaxation time is 10.4 ns at room temperature and increases with increasing excitation power, which demonstrates the high quality of the InGaAsP material. However, the relaxation time shows an S-shape variation with increasing temperature： it increases at temperatures lower than 50 K, and then decreases between 50—150 K, and increases again when temperature is over 150 K. According to the effect of temperature and the non-radiative recombination center concentration on the carrier relaxation time, the recombination mechanism of S-shape variation can be explained by the carrier relaxation dynamics.