Mobility lifetime product in doped and undoped nanocrystalline CdSe

• Published in: Thin solid films Vol. 548; pp. 406 - 410
• Main Authors: Tripathi, S.K., Al-Kabbi, Alaa S., Sharma, Kriti, Saini, G.S.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 02.12.2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Doping; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials science; Mobility lifetime (μτ) product; Nanocrystalline; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Photoconduction and photovoltaic effects; photodielectric effects; Physics; Thin films; X- and γ-ray instruments and techniques; X- and γ-ray sources, mirrors, gratings and detectors; Thin films; Mobility lifetime (μτ) product; Doping; Nanocrystalline; Temperature dependence; Voltage dependence; Transport properties; Semiconductor materials; Radiation detectors; Charge transport; Nanostructures; Physical properties; Energy gap; Lifetime; Photoconductivity; Recombination process; Figure of merit; Nanocrystal
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.09.008

This paper reports the effect of doping on the charge transport in nanocrystalline CdSe thin film. The X-ray study confirms that the doping is achieved and the physical properties are improved. The energy resolution of a semiconductor radiation detector depends on the charge transport properties of the semiconductor and the mobility-lifetime (μτ) product is a key figure of merit for the charge transport. μτ product in nanocrystalline CdSe, CdSe:In and CdSe:Zn thin films has been estimated from temperature dependence of the photoconductivity, which increases with increase in temperature and doping. Also, μτ product of electrons in pure and doped nanocrystalline CdSe thin films has been determined by spectral photoconductivity at different applied voltages. Both the μτ and photoconductivity increase linearly with the bias voltage but the wavelength dependence remains qualitatively similar in all samples. The μτ products increase at photon energies>energy gap, which indicates that the recombination process depends on the excitation energy. The doped CdSe thin films have higher drift length in comparison with undoped films which suggest that these thin films can be used in charge collecting devices. •The structure of thin films has been studied using X-ray diffraction.•Spectral dependence of μτ product in pure and doped nc-CdSe thin films is studied.•The mobility-lifetime product shows dependence on temperature and doping type.•The drift length increases linearly with increasing applied field and doping.•The transport properties of nc-CdSe thin films are enhanced with doping.