新的电调制反射谱技术及其应用

A New Type of Electromodulation Spectroscopy and Its Application

提出一种微接触电调制反射谱(LCER)测试方法,该方示与无接触电调制反射(CER)谱相比较,可极大降低调制电压。给出了自制的详细样品架结构,测量了InGaAs/GaAs量子阱样品,并与光调制反射谱(PR)相比较,结果证实了此方法的可行性和高光谱灵敏度,表明样品与电极的轻微接触既对测量结果没有明显的影响,又可简化测试条件,降低对测量环境的要求,是研究半导体材料和微结构一种方便而又有效的方法。

A new type of light-contact electroreflectance （LCER） spectroscopy technique was proposed. The measurement of the modulation spectroscopy can be simplified by using this method. The structure of the sample holder was presented in detail. The required amplitude of modulation voltage can be largely reduced by comparing with that of OER and the mechanism is analyzed qualitatively. The experimental results in InGaAs/GaAs quantum well samples by using LCER technique are presented and indicate the high spectral sensitivity and high spectral resolution of LCER. Compared with the experimental results of photoreflectance（PR）, it is shown that both spectra of LOER and PR coincide with each other and the experimental results are not influenced by the light contact between the surface of the sample and the electrode. It is concluded that LCER is an effective and convenient method for the study of semiconductor materials and semiconductor quantum wells.