Abstract
A single molecular precursor solution is described for the deposition of CuIn(S,Se)2 (CIS) film onto Mo coated glass substrates by spin coating followed by annealing in Se atmosphere. Characterization of the films by X-ray diffraction, Raman spectroscopy and scanning electron microscopy demonstrates the formation of a highly homogenous and compact 1.1 m thick CIS layer, with a MoSe2 under-layer. Atomic force microscopy reveals the presence of spherical grains between 400-450 nm, featuring surface corrugation in the range of 30 nm. Film composition is found to be in close agreement with that of the precursor solution. Diffuse reflectance spectroscopy shows a direct band gap (Eg) of 1.36 eV. Intensity and temperature dependence photoluminescence spectra show characteristic features associated with a donor-acceptor pair recombination mechanism, featuring activation energy of 34 meV. Over 85 solar cell devices with the configuration Mo/CIS/CdS/i-ZnO/Al:ZnO/Ni-Al and an total area of 0.5 cm2 were fabricated and tested. The champion cell shows a power efficiency of 3.36 % with an open circuit voltage of 521 mV and short circuit current of 14 mA/cm2 under AM 1.5 illumination and an external quantum efficiency above 60%. Overall variation in each of solar cell parameters remains below 10% of the average value, demonstrating the remarkable homogeneity of this solution processing method. To understand the limitation of devices, the dependence of the open-circuit voltage and impedance spectra upon temperature were analyzed. The data reveal that the CuIn(S,Se)2/CdS interface is the main recombination pathway with an activation energy of 0.79 eV as well as the presence of two ‘bulk’ defect states with activation energies of 37 meV and 122 meV. We also estimated that the MoSe2 under-layer generates back contact barrier of 195 meV.
Original language | English |
---|---|
Pages (from-to) | 2301-2308 |
Number of pages | 8 |
Journal | ACS Applied Materials and Interfaces |
Volume | 9 |
Issue number | 3 |
Early online date | 29 Dec 2016 |
DOIs | |
Publication status | Published - 25 Jan 2017 |
Keywords
- Solar cells
- Culn(S,Se)2
- Thin films
- Solution processing
- Recombination losses
- Impedance spectroscopy
Fingerprint
Dive into the research topics of 'Single molecular precursor solution for CuIn(S,Se)2 thin films photovoltaic cells: structure and device characteristics'. Together they form a unique fingerprint.Datasets
-
Single Molecular Precursor Solution for CuIn(S,Se)2 Thin Films Photovoltaic Cells: Structure and Device Characteristics
Tiwari, D. (Creator) & Fermin, D. J. (Creator), University of Bristol, 8 Feb 2017
DOI: 10.5523/bris.2h3o9mboymwsi2cl9hn9o2v9do, http://data.bris.ac.uk/data/dataset/2h3o9mboymwsi2cl9hn9o2v9do
Dataset