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An in situ thermal annealing process (iTAP) has been introduced before the common ex situ cadmium chloride (CdCl2) annealing to improve crystal quality and morphology of the CdTe thin films after pulsed laser deposition of CdS/CdTe heterostructures. A strong correlation between the two annealing processes was observed, leading to a profound effect on the performance of CdS/CdTe thin film solar cells. Atomic force microscopy and Raman spectroscopy show that the iTAP in the optimal processing window produces considerable CdTe grain growth and improves the CdTe crystallinity, which results in significantly improved optoelectronic properties and quantum efficiency of the CdS/CdTe solar cells. A power conversion efficiency of up to 7.0% has been obtained on thin film CdS/CdTe solar cells of absorber thickness as small as 0.75 μm processed with the optimal iTAP at 450°C for 10–20 min. This result illustrates the importance of controlling microstructures of CdTe thin films and iTAP provides a viable approach to achieve such a control. [ABSTRACT FROM AUTHOR]

Sb 2 Se 3 is a promising absorber for thin film solar cells due to its nontoxicity, low cost, earth abundance and excellent photovoltaic properties. However, few reports focus on Sb 2 Se 3 thin films prepared by pulsed laser deposition (PLD). Here we successfully deposited Sb 2 Se 3 thin films at different substrate temperatures by PLD. Structural, morphological, compositional, optical and electrical properties of Sb 2 Se 3 thin films were characterized. Results show that Sb 2 Se 3 thin films exhibit orthorhombic phase with good crystallinity and higher substrate temperature can distinctly improve crystal quality. Optical band gap is about 1.30 eV, 1.20 eV, 1.18 eV and 1.16 eV for Sb 2 Se 3 thin films deposited at 370 °C, 390 °C, 410 °C and 430 °C, respectively. In addition, the atomic ratio of selenium to antimony is 3/2, entirely consistent with the stoichiometry ratio of Sb 2 Se 3. Image 1 • Sb 2 Se 3 thin films were prepared on glass at different substrate temperatures by KrF PLD. • The atomic ratio of selenium to antimony was 3/2, entirely consistent with the stoichiometry ratio of Sb 2 Se 3. • Optical band gap was estimated to be 1.30 eV, 1.20 eV, 1.18 eV and 1.16 eV for Sb 2 Se 3 thin films deposited at 370 °C, 390 °C, 410 °C and 430 °C respectively. • High substrate temperature improved crystal quality. [ABSTRACT FROM AUTHOR]

AlSb films which are a promising absorber layer for thin film solar cells were grown on glass substrate at different substrate temperature ranging from room temperature to 400 °C on glass substrates using aluminum-antimony alloying target by pulsed laser deposition (PLD) technique. Structural, optical and electrical properties of AlSb thin films were studied by X-ray diffraction (XRD), ultraviolet–visible spectrophotometer and a home-made four-probe-contact high temperature system respectively. XRD pattern shows that AlSb film is amorphous at room temperature, but when substrate temperature is higher than 100 °C, AlSb films present cubic phase structure with the preferential orientation of (111) plane. And intensity of diffraction peaks of AlSb film prepared at substrate temperature of 200 °C are stronger than that of other substrate temperature. The electrical measurement results show that conductivity activation energy of AlSb film is 0.25 eV and 0.28 eV. The indirect optical band gap is about 1.63 eV, which is very close to its theoretical value of 1.62 eV. The results of energy dispersive spectrometer (EDS) indicated the ratio of Al to Sb of AlSb films is about 1:1. [ABSTRACT FROM AUTHOR]

Aluminum antimony (AlSb) is a potential absorber for solar cells. In present work, we fabricated AlSb thin films by using pulsed laser deposition method, and investigated the influence of substrate temperature on the structural, electrical and optical properties of AlSb thin films. The results suggested that the AlSb thin films were crystal when the substrate temperature was higher than 300 °C. The average grain size of AlSb films increased and the electrical resistivity decreased with the increase of substrate temperature. At the optimized temperature of 400 °C, the optical band gap of AlSb thin film was 1.82eV. The simulated device performance of ZnS/AlSb ultra-thin solar cells showed that the power conversion efficiency was 18.01% and the quantum efficiency values were higher than 55% in the visible range. [ABSTRACT FROM AUTHOR]