Kumar Praveen, Thangaraj R
Semiconductors Laboratory, Department of Applied Physics, Guru Nanak Dev University, Amritsar 143005, India.
J Phys Condens Matter. 2009 Sep 16;21(37):375102. doi: 10.1088/0953-8984/21/37/375102. Epub 2009 Aug 11.
The effects of phase separation on the structure and photoconductivity kinetics in Sn(x)Sb(20)Se(80-x) (x = 10,11,12.5) glassy films have been studied. Crystalline peaks for SnSe(2), Sn(2)Sb(4)Se(8) and Sn(4)Sb(4)Se(10) phases are found in x = 12.5 films, while Sb(2)Se(3) is the other major phase revealed from x-ray diffraction studies. The optical gap remains constant at 1.55 eV for x = 10,11 samples and then decreases to 1.50 eV for the x = 12.5 film, while a blueshift in reflectivity maxima (R(max)) has been observed with Sn content. An increase in room temperature conductivity and a decrease in dc activation energy with Sn content have been observed. Bimolecular recombination is the dominant recombination process under steady state illumination for all of the samples. Decay of photocurrent (after cessation of light) fits well to a stretched exponential function; the decay time constant and dispersion parameter have been discussed. The growth of network connectivity with an increase in compositional/configurational disorder induces states in the mobility gap and affects the structure of band tails. These results have been interpreted in the light of the barrier cluster model developed for chalcogenide glasses.
研究了相分离对Sn(x)Sb(20)Se(80 - x)（x = 10、11、12.5）玻璃薄膜结构和光电导动力学的影响。在x = 12.5的薄膜中发现了SnSe₂、Sn₂Sb₄Se₈和Sn₄Sb₄Se₁₀相的结晶峰，而X射线衍射研究表明Sb₂Se₃是另一个主要相。对于x = 10、11的样品，光学带隙保持在1.55 eV不变，而对于x = 12.5的薄膜，光学带隙降至1.50 eV，同时观察到反射率最大值（R(max)）随Sn含量发生蓝移。观察到室温电导率随Sn含量增加，直流激活能随Sn含量降低。在稳态光照下，双分子复合是所有样品中的主要复合过程。光电流衰减（光照停止后）很好地符合拉伸指数函数；讨论了衰减时间常数和色散参数。随着成分/构型无序度的增加，网络连通性的增长在迁移率带隙中诱导出态，并影响带尾结构。这些结果已根据为硫族化物玻璃开发的势垒簇模型进行了解释。
