【摘要】 利用Raman显微镜系统对4块用液相外延(LPE)方法在Cd0 96Zn0 04Te衬底上生长的Hg0 8Cd0 2Te外延薄膜样品,在100～5000cm-1光谱范围进行测量,在实验曲线中除了观察到与碲镉汞材料晶格振动相符的类 HgTe的光学振动横模(TO1模)和纵模(LO1模)的Raman散射峰、类 CdTe光学振动横模(TO2模)和纵模(LO2模)混合的Raman散射峰以及来源于TO1+LO1的二级Raman散射峰外,在1000～5000cm-1光谱范围首次发现了LPE碲镉汞薄膜的显微荧光峰,该显微荧光的发光范围换算为电子伏特标度为1 34～1 83eV,发光中心位于2750cm-1即1 62eV,发光峰的半高宽(FWHM)约为0 25eV。通过分析指出,该显微荧光来源于碲镉汞外延层中阴性离子空位与材料导带底的共振能级的发光。更多还原

【Abstract】 The fundamental physical properties of Hg1-xCdxTe make it an excellent candidate material for infrared photoelectric detectors. Recently, much attention has been paid to Hg1-xCdxTe films grown by different epitaxial techniques on the substrate Cd1-yZny Te due to the possibility of fabricating large area detectors as well as high precision focal plane array detectors. Investigations of the phonon vibration spectra for Hg1-xCdxTe are necessary to understand the lattice dynamics and to obtain structure information about the material. In this paper, the microRaman and microphotoluminescence spectra of four LPE Hg1-xCdxTe epitaxial film samples were measured at room temperature within the spectral range of 100cm-1 to 5 000cm-1. The microphotoluminescence results show that there is an anion vacancy resonance level far up in the conduction band, about 1.47eV above the conduction band edge of the Hg1-xCdxTe epitaxial films. In the microRaman spectra of samples there are four main Raman peaks 120, 138, 155 and 261cm-1 are observed. Raman peaks 120cm-1 belongs to HgTelike TO1 phonon vibrational mode, 138cm-1 belongs to HgTelike LO1 phonon vibrational mode, 155cm-1 occurs due to the CdTelike LO1 and CdTelike TO1 phonon mixed vibration, and 261cm-1 comes from the twophonon mode TO1(HgTelike)+LO1(HgTelike). Our results definitely show that the microphotoluminescent structure is mainly due to the improvement in quality of the Hg1-xCdxTe epilayer.更多还原