Transparent and conductive CdS:Ca thin films for optoelectronic applications
[ X ]
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer Heidelberg
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This paper presents the structural, morphological, optical and electrical evolution of Ca-doped CdS thin films. Non-doped and Ca-doped CdS samples with various amounts of Ca atoms (from 0 to 10 at.% with an increasing step of 2 at.%) were grown by spray pyrolysis route on glass slides. The structural investigation by X-ray diffraction showed that Ca-doping distorted CdS structure until 8 at.% Ca-doping and then a slight improvement in the intensity of (101) peak was obtained for 10 at.% Ca-doping compared to the other Ca-doping samples. Morphological analysis displayed a grain growth for a low amount of Ca-doping whereas higher concentration of Ca-doping led to a reduction in the grain size of CdS thin films. More stoichiometric CdS specimens were obtained after various amounts of Ca-doping according to energy dispersive X-ray spectroscopy data. Transparency of the CdS samples enhanced remarkably with the incorporation of Ca atoms in CdS with a particular concentration of 10 at.%. Tauc's plot investigation illustrated that the bandgap score of samples changed from 2.54 eV for non-doped CdS to 2.48 eV for 4 at.% Ca-doped CdS thin films. Further increase of Ca-doping doesn't vary the bandwidth of CdS samples. Photoluminescence data indicated that Ca-doped CdS thin films had lower intrinsic defects compared with non-doped CdS one. The electrical examination demonstrated that the carrier density of CdS thin films increased till 6 at.% Ca-doping and then decreased further increase of Ca-doping. However, resistivity values exhibited the opposite behavior accordingly. In conclusion, it can be pronounced that 6 at.% Ca-doped CdS thin films are the optimum specimen to be used as an effective transparent and conductive material in the optoelectronic devices.
Açıklama
Anahtar Kelimeler
CdS thin films, Ca-doping, Spray pyrolysis, Optical properties, Electrical properties
Kaynak
Applied Physics A-Materials Science & Processing
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
126
Sayı
7
