Hot Wall Epitaxy(HWE)법에 의한 Cdln2S4단결정 박막 성장과 열처리 효과

Abstract

A stoichiometric mixture of evaporating materials for CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by hot wall epitaxy(HWE) system. The source and substrate temperatures were 630 <TEX>$\^{C}$</TEX> and 420 <TEX>$\^{C}$</TEX>, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films measured from Hall effect by van der Pauw method are 9.01<TEX>$\times$</TEX>10<TEX>$\^$</TEX>16/ cm<TEX>$\^$</TEX>-3/ and 219 ㎠/V<TEX>$.$</TEX>s at 293 K, respectively. From the optical absorption measurement, the temperature dependence of energy band gap on CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films was found to be Eg(T) ＝ 2.7116 eV - (7.74 <TEX>$\times$</TEX> 10<TEX>$\^$</TEX>-4/ eV) T<TEX>$\^$</TEX>2//(T＋434). After the as-grown CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films was annealed in Cd-, S-, and In-atmospheres, the origin of point defects of CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of V<TEX>$\_$</TEX>cd/, V<TEX>$\_$</TEX>s/, Cd<TEX>$\_$</TEX>int/ and S<TEX>$\_$</TEX>int/ obtained by PL measurements were classified as donors or accepters type. And we concluded that the heat-treatment in the S-atmosphere converted CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films to an optical p-type. Also, we confirmed that In in CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/GaAs did not from the native defects because In in CdIn<TEX>$\_$</TEX>2/S<TEX>$\_$</TEX>4/ single crystal thin films existed in the form of stable bonds.