Studies on low-cost and environmentally-benign carbon solar cell

Amorphous carbon has attracted attention as an environmentally begin and cheap solar cell over amorphous silicon。Thin films amorphous carbon(a-C)have been deposited using camphor as a source materials by different deposition methods，such as ion beam sputtering，pyrolysis and pulsed laser deposition.The films are subjected to various standard characterization techniques in order to tailor the required structural and opto-electrical properties for device applications.The effects of deposition parameters and annealing temperatures on the properties of carbon thin films have been investigated.The optical band gap increased with increasing the sputtering power or decreasing the deposition temperature，and 1 eV has been obtained at the optimum conditions。The film showed n type by the phosphorous doping.The pyrolyzed film showed p type with the carrier concentration of 10 I D 121 I D 1 to 10 I D 122 I D 1厘米I D 1-3 I D 1.For the films deposited by laser pulse deposition，the optical band gap showed0.8 eV，whereas that deposited using graphite target showed0.6 eV optical band gap.Both p-and n-type of carbon films have been obtained either through controlling the reposition parameters of a particular method or by doping.Solar cells of various configurations，such as n-C/p-Si，p-C/n-Si and n-C/p-C/p-Si，have been fabricated and their photoresponse characteristics are studied.The highest efficiency has been obtained by the cell configuration of n-C/p-C/p-Si.Effects of substrate temperature on the photovoltaic properties are also investigated.

Amorphous carbon has attracted attention as an environmentally begin and cheap solar cell over amorphous silicon. Thin films amorphous carbon (a-C) have been deposited using camphor as a source materials by different deposition methods, such as ion beam sputtering, pyrolysis and pulsed laser deposition. The films are subjected to various standard characterization techniques in order to tailor the required structural and opto-electrical properties for device applications. The effects of deposition parameters and annealing temperatures on the properties of carbon thin films have been investigated. The optical band gap increased with increasing the sputtering power or decreasing the deposition temperature, and 1 eV has been obtained at the optimum conditions. The film showed n type by the phosphorous doping. The pyrolyzed film showed p type with the carrier concentration of 10ィイD121ィエD1 to 10ィイD122ィエD1 cmィイD1-3ィエD1. For the films deposited by laser pulse deposition, the optical band gap showed 0.8 eV, whereas that deposited using graphite target showed 0.6 eV optical band gap. Both p- and n- type of carbon films have been obtained either through controlling the reposition parameters of a particular method or by doping. Solar cells of various configurations, such as n-C/p-Si, p-C/n-Si and n-C/p-C/p-Si, have been fabricated and their photoresponse characteristics are studied. The highest efficiency has been obtained by the cell configuration of n-C/p-C/p-Si. Effects of substrate temperature on the photovoltaic properties are also investigated.