Abstract
This paper investigates the properties of thermally evaporated p-i-n junction thin film microcrystalline silicon (μc-Si) solar cells on polyimide substrate with multiple light trapping schemes. Hall effect measures doping density of 6.63 x 1018 cm-3 for 500 nm p-type Si and 4.87 x 1019 cm-3 for 120 nm n-type Si produced by co-evaporation of silicon with aluminium and antimony respectively. Raman spectra reveals a peak 511 cm-1 with a shoulder at 480 cm-1, suggesting microcrystalline nature of the intrinsic 800 nm absorber layer with crystalline volume fraction of ~65%. High resolution X-ray diffraction illustrates that μc-Si grains are in (111) orientation from the peak at 28.9° (orthorhombic crystal structure) and full width at half maximum of 0.2952°. UV-Vis spectrophotometer shows that absorption coefficient of the μc-Si absorber has a gradual increase from 1.1 eV towards higher photon energy with a fairly high absorption (~104 cm-1) in the visible region (1.55 – 3.10 eV). The band gap (Eg) of the μc-Si absorber layer is derived to be ~1.2 eV from Tauc plot. The best solar cell records short-circuit current = 8mA, open-circuit voltage = 410 mV and efficiency = 2.0% from current-voltage curve owing to light trapping strategies within the cell..
Keywords
Thermal evaporation, Polyimide, Thin film microcrystalline silicon solar cells, X-ray diffraction, Light trapping.
Citation
M. Z. PAKHURUDDIN, K. IBRAHIM, A. ABDUL AZIZ, Thermally evaporated thin film microcrystalline silicon solar cells on polyimide substrate with multiple light trapping schemes, Optoelectronics and Advanced Materials - Rapid Communications, 8, 3-4, March-April 2014, pp.255-259 (2014).
Submitted at: Jan. 14, 2013
Accepted at: March 13, 2014