HYDROSTATIC-PRESSURE EFFECTS ON THE EXCITONS AND EXCITON-PHONON INTERACTION IN BII3 CRYSTALS
HYDROSTATIC-PRESSURE EFFECTS ON THE EXCITONS AND EXCITON-PHONON INTERACTION IN BII3 CRYSTALS
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DOI：
10.1143/jpsj.62.1048
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发表时间：
1993-03-01
影响因子：
1.7
通讯作者：
KARASAWA, T
中科院分区：
文献类型：
--
作者：
KURISU, H;KOMATSU, T;KARASAWA, T
在77 K和300 K的静水压力高达1.5 GPa的条件下，测量了BiI3晶体中激子的光吸收和光致发光。直接激子吸收带在压力下出现红移，红移系数为-1.0 X 10(2) meV/GPa。该带的低能尾在所有压力下都服从厄巴赫规则。当压力从大气压增加到1 GPa时，Urbach规则中的陡度系数sigma从1.03增加到1.22。自捕获激子态的光致发光强度随着压力的增加而减弱，而带边光致发光强度则增强。从激子-声子相互作用的变化引起的自捕获激子态的不稳定性出发，讨论了压力作用下的光致发光强度和陡度系数的变化。
Optical absorption and photoluminescence due to excitons in BiI3 crystals have been measured under hydrostatic pressures up to 1.5 GPa at 77 K and 300 K. The direct exciton absorption band shows a red shift under pressure with a coefficient of -1.0 X 10(2) meV/GPa. The low energy tail of this band obeys the Urbach rule under all pressures. The steepness coefficient sigma in the Urbach rule increases from 1.03 to 1.22 as pressure increases from atmospheric pressure to 1 GPa. The intensity of a photoluminescence from a self-trapped exciton state diminishes with increasing pressure, which is complemented by strengthening of the band edge photoluminescence. The behavior of the photoluminescence intensities and the steepness coefficient under pressure is discussed in terms of the instability of the self-trapped exciton state due to the change in the exciton-phonon interaction.