N. Poornima

Defect analysis of CZTS thin films using photoluminescence technique

Photoluminescence (PL) technique was used to identify defect levels in Copper Zinc Tin Sulphide (CZTS) thin films deposited using Chemical Spray Pyrolysis (CSP). Films were deposited for different Cu:Zn:Sn:S ratios. An emission was observed at 0.8 eV. It was monitored from 15K to room temperature and activation energy was calculated. Excitation power dependent studies were done to analyze the type of transition.

Photoluminescence studies on off-stoichiometric defects in sprayed CZTS thin films

Photoluminescence (PL) technique was used for studying the defects in Copper Zinc Tin Sulphide (CZTS) thin films deposited by Chemical Spray Pyrolysis (CSP). Measurements were done on films prepared for different Cu:Zn:Sn:S ratios. An emission at 0.805 eV was monitored from 15 K to room temperature and activation energy was calculated. Excitation power dependent studies were done to analyze the type of transition.

Predicting The Performance Parameters of In2S3/MEH‐PPV Heterojunction Using Photoluminescence Technique

Photoluminescence (PL) technique has been put into use for analysing In2S3/MEH‐PPV heterojunction for the first time. Strong luminescence of the polymer absorber MEH‐PPV has been exploited here to predict the properties of the cell. The underlying theory is the dependence of PL intensity on quasi Fermi level separation, which is a measure of the open‐circuit voltage. Predicted voltages from PL were very much in communion with those obtained from J‐V measurements. Thus the choice of PL for noninvasive analysis of solar cells can be justified from the present work.

Preparation and Characterization of Spray Pyrolysed ZnS Thin Films and the Effect of Chlorine Doping

Employing low cost spray pyrolysis technique, ZnS thin films were prepared, using different precursors and by varying sulfur concentration. Effect of chlorine doping was studied on all the samples. Characterization of the sprayed ZnS thin films was done using XRD, UV‐Vis‐NIR spectrophotometer and fluorimeter. ZnS thin films prepared using zinc chloride precursor showed better crystallinity. An obvious variation in band gap and photoluminescence was observed with variation in sulfur concentration in ZnS samples.