Electrodeposited CuInSe2 Thin Film Junctions
We have investigated thin films and junctions based on copper indium diselenide (CIS) which have been grown by electrochemical deposition. CIS is a leading candidate for use in polycrystalline thin film photovoltaic solar cells. Electrodeposition is a cost-effective method for producing thin-film CIS. We have produced both p and n type CIS thin films from the same aqueous solution by simply varying the deposition potential. A CIS pn junction was deposited using a step-function potential. Stoichiometry of the single layer films was determined by energy dispersive spectroscopy. Carrier densities of these films increased with deviation from stoichiometry, as determined by the capacitance versus voltage dependence of Schottky contacts. Optical bandgaps for the single layer films as determined by transmission spectroscopy were also found to increase with deviation from stoichiometry. Rectifying current versus voltage characteristics were demonstrated for the Schottky barriers and for the pn junction.
Non‐vacuum methods for formation of Cu(In, Ga)(Se, S)2 thin film photovoltaic absorbers
Polycrystalline thin films of copper indium diselenide and its alloys with gallium and sulphur (CIGS) have proven to be suitable for use as absorbers in high‐efficiency solar cells. Record efficiency devices of 20% power conversion efficiency have been produced by co‐evaporation of the elements under high vacuum. However, non‐vacuum methods for absorber deposition promise significantly lower capital expenditure and reduced materials costs, and have been used to produce devices with efficiencies of up to 14%. Such efficiencies are already high enough for commercial up‐scaling to be considered and several companies are now trying to develop products based on non‐vacuum deposited CIGS absorbers. This article will review the wide range of non‐vacuum techniques that have been used to deposit CIGS thin films, highlighting the state of the art and efforts towards commercialization. Copyright © 2009 John Wiley & Sons, Ltd.
The lights that failed: European international history, 1919-1933
PART I: THE RECONSTRUCTION OF EUROPE, 1918-1929 1. The Hall of Mirrors: Peacemaking in the West 2. Distant Frontiers: Peacemaking in the East 3. Revolution from the Left: The Soviet Union and the Post-War Settlement 4. The Primacy of Economics: Reconstruction in Western Europe, 1919-1924 5. The Primacy of Nationalism: Reconstruction in Eastern and Central Europe 6. Revolution from the Right: Italy, 1919-25 7. The Geneva Dream: The League of Nations and Post-War Internationalism 8. New Dawn? Stabilisation in Western Europe after Locarno 9. Faltering Reconstruction: Cracks in the Locarno Facade 10. Troubled Waters: Uncertainties in Italy, Eastern Europe and the Soviet Union 11. Faltering Internationalism: Disarmament and Security after Locarno Conclusion: Europe Reconstructed? PART II: THE HINGE YEARS, 1930-1933 12. The Diplomacy of the Depression: Economics and Foreign Policy 13. Beyond Europe: The Manchurian Crisis 14. The Poisoned Chalice: The Pursuit of Disarmament Conclusion: The Hinge Years Appendices Select Bibliography