Growth, characterization and transport properties of Pb𝑥Zn1â€�?�ð�?�¥S mixed crystals

Bulletin of materials science

E Nagabushan¹  K Yadaiah³  M Nagabhushanam²  B Rajam¹  D Jaya Prakash¹ 

[1] University College of Technology, Osmania University, Hyderabad 500 007, India$$University College of Technology, Osmania University, Hyderabad 500 007, IndiaUniversity College of Technology, Osmania University, Hyderabad 500 007, India$$;Department of Physics, University College of Science, Osmania University, Hyderabad 500 007, India$$Department of Physics, University College of Science, Osmania University, Hyderabad 500 007, IndiaDepartment of Physics, University College of Science, Osmania University, Hyderabad 500 007, India$$;S.V. Degree and P.G. College, Suryapeta, Nalagonda (Dist) 508 213, India$$S.V. Degree and P.G. College, Suryapeta, Nalagonda (Dist) 508 213, IndiaS.V. Degree and P.G. College, Suryapeta, Nalagonda (Dist) 508 213, India$$

关键词: Mixed;    semiconductors;    co-precipitation;    optical characterization;    thermoelectric power.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The polycrystalline Pb_�?Zn_{1�?����?}S semiconductor powder with (0 �? �?�? 0.5) has been prepared by controlled co-precipitation method from an alkaline medium using thiourea as a sulphide ion source. Pellets are made with these powders applying 10 ton/sq.cm. pressure and sintered at 800°C for 2 h in nitrogen atmosphere. X-ray studies of these samples have indicated that the compounds are polycrystalline in nature with mixed hexagonal and cubic structure of ZnS and cubic structure of PbS. Lattice parameters (�? and �?) of all the compounds are determined from the X-ray data and are found to decrease nonlinearly with increase in Pb concentration (�?). It is also observed that the grain size of the crystallites increases in samples with �? = 0�??0.5. Scanning electron micrographs have shown that both cubic and hexagonal crystallites are present in the mixed crystals. The electrical conductivity in Pb_�?Zn_{1�?����?}S is found to decrease with increase in composition (�? = 0�??0.5), whereas it increases at all temperatures in all samples. Mobility of charge carrier concentration is found to increase with increasing temperature. The increase in carrier mobility in Pb_�?Zn_{1�?����?}S samples may be due to reduced grain boundary potential. In Pb_�?Zn_{1�?����?}S samples with �? = 0�??0.3, the sum of the activation energy due to charge carriers and grain boundary potential is equal to the activation energy due to conductivity.

【 授权许可】

Unknown