Positive temperature variation of the bandgap energy in AgGaSe2
Positive temperature variation of the bandgap energy in AgGaSe2
复制标题
AgGaSe2 中带隙能量的正温度变化
DOI：
10.1002/pssa.200669526
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
S. Adachi
中科院分区：
文献类型：
--
作者：
S. Ozaki;M. Sasaki;S. Adachi
测量了三元黄铜矿半导体AgGaSe_2在T=15-300K下的光吸收、光反射和光致发光光谱。由光吸收测量得到的AgGaSe_2的直接带隙能E_0A在低温下表现出反常的温度依赖性。合成系数∂E0A/∂T在T<；70K为正，在70K以上为负。PR谱还表明，在T<；70K，禁带能E0A和E0B与温度呈正相关。这些结果被成功地考虑到低温下的负晶格热膨胀。(2006 Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
Optical‐absorption, photoreflectance (PR), and photoluminescence spectra have been measured on the ternary chalcopyrite semiconductor AgGaSe2 at T = 15–300 K. The direct‐bandgap energy E 0A of AgGaSe2 determined from the optical absorption measurements shows unusual temperature dependence at low temperatures. The resultant coefficient ∂E 0A/∂T is positive at T < 70 K and negative above 70 K. The PR spectra also indicate positive temperature dependence of the bandgap energies, E 0A and E 0B, at T < 70 K. These results have been successfully explained by taking into account the negative lattice thermal expansion at low temperatures. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)