Photogenerated carriers in SrTiO3 probed by mid-infrared absorption
Photogenerated carriers in SrTiO3 probed by mid-infrared absorption
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DOI：
10.1143/jpsj.75.023703
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发表时间：
2006-02-01
影响因子：
1.7
通讯作者：
Nanba, T
中科院分区：
文献类型：
--
作者：
Okamura, H;Matsubara, M;Nanba, T
为了研究光生载流子的性质，测量了SrTiO_3在带隙以上光激发下的红外吸收光谱。在光激发下，在整个中红外区出现了一个宽的吸收带，这是由于光生载流子占据隙内态的吸收。光诱导吸收强烈依赖于温度，甚至低于35 K，其中的平均光生载流子密度几乎是恒定的。数据表明，由光生载流子占据的间隙态的密度是高的，并且分布在延伸到带边的宽的能量范围内。
Infrared absorption spectra of SrTiO3 have been measured under above-band-gap photoexcitations to study the properties of photogenerated carriers, which should play important roles in previously reported photoinduced phenomena in SrTiO3. A broad absorption band appears over the entire mid-infrared region under photoexcitation, which is attributed to absorption by the photogenerated carriers occupying in-gap states. The photoinduced absorption is strongly dependent on temperature even below 35 K, where the average photocarrier density is nearly constant. The data show that the density of in-gap states occupied by the photocarriers is high and distributed over a wide energy range extending to the band edges.