TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Process: The process (P1) further involves growing cadmium chloride (CdCl2) cap layer by metal organic chemical vapor deposition (MOCVD) in situ; annealing the cell in situ; and cooling the cell in situ. The process (P1) involves plasma surface etching the technique to lower the thickness of the cadmium sulfide layer. The process (P1) is carried out in a reduced pressure or atmospheric pressure MOCVD reactor. In the process (P1), the photovoltaic cell is formed on a suitable substrate or superstrate material includes aluminosilicate (or soda lime) glass, or polymer. The substrate or superstrate has a patterned contact layer. The superstrate or substrate is cleaned before the layers are grown. The precursor is used. The carrier gas and precursors are delivered by unit of stream diffusers or spray showerheads. The thickness and growth properties of the layers during MOCVD are monitored using a triple wavelength interferometer. The cadmium sulfide (CdS) window layer is grown from dimethyl cadmium (DMCd) and ditertiarybutylsulfide (DtBS) organo-metallic precursors under hydrogen atmosphere. The window layer is grown at a substrate temperature of 240-410 (preferably 250-400, especially 315)degreesC. The II:VI precursor ratio of the window layer is around 1. The window layer is grown at a total gas flow in the reactor of 1000-10000 (preferably 3355) sccm. The window layer is grown at a cadmium partial pressure of 1x10-5-1\%10-2 (preferably 1x10-4-1x10-3, especially 2.7x10-4) atmospheres. The cadmium sulfide window layer is grown from dimethylcadmium (DMCd), diethylzinc (DEZn) (or dimethylzinc (DMZn)) and ditertiarybutylsulfide (DtBS) organo-metallic precursors under hydrogen atmosphere. The cadmium sulfide window layer is doped with chlorine. The chlorine doping is achieved by the additional use of a precursor such as tertiarybutylchloride (tBuCl). The cadmium telluride absorber layer is alloyed with zinc. The cadmium telluride absorber layer is doped with arsenic. The doping is even throughout the layer. The doping is graded over the layer. The doping is concentrated at particular places along the structure. The cadmium telluride is grown from dimethylcadmium and diisopropyltelluride organo-metallic precursors under hydrogen atmosphere. The cadmium telluride absorber layer is grown from dimethylcadmium, diethylzinc (or dimethylzinc (DMZn)) and diisopropyltelluride organo-metallic precursors under hydrogen atmosphere. The cadmium telluride absorber layer is grown from dimethylcadmium, diisopropyltelluride and tris(dimethylamino)arsine organo-metallic precursors under hydrogen atmosphere. The absorber layer is grown at a substrate temperature of 280-460 (preferably 300-450, especially 390)degreesC. The absorber layer is grown at a total gas flow in the reactor is 1000-10000 (preferably 4400) sccm. The absorber layer is grown at a cadmium partial pressure of 1x10-5-1\%10-2 (preferably 1x10-4-1x10-3, especially 2x10-4) atmospheres. The arsenic doping is carried out using a double dilution line. The absorber layer is grown at an arsenic partial pressure of 1x10-10-1x10-4 (preferably 1x10-9-1x10-5, especially 1.5x10-6) atmospheres. The cadmium chloride cap layer is grown from dimethylcadmium (DMCd) and tertiarybutylchloride (tBuCl) or n-hexylchloride (nHexCl) organo-metallic precursors under a hydrogen atmosphere. The cap layer is grown at a substrate temperature of 100-460 (preferably 150-400, especially 300)degreesC. The cap layer is grown at a total gas flow in the reactor of 1000-10000 (preferably 3500) sccm. The cap layer is grown at a cadmium partial pressure of 1x10-5-1\%10-2 (preferably 1x10-4-1x10-3, especially 2.8x10-4) atmospheres. The simultaneous cap layer growth and annealing takes place at 240-520 (preferably 400)degreesC. The simultaneous cap layer growth and annealing takes place at a total gas flow in the reactor of 1000-10000 sccm. The simultaneous cap layer growth and annealing takes place for 5 minutes to 1 hour. The simultaneous cap layer growth and annealing takes place at a precursor partial pressure of 1x10-10-1\10-3 atmosphere. The photovoltaic cell is cooled to room temperature under hydrogen, subsequent to annealing. Once the photovoltaic cell is cooled, it is exposed to ambient air for metallization. Once the cell is cooled, its photo-electric properties are measured. Once the cell is cooled, it is sliced into several individual devices. Two sides of the individual sliced devices are subsequently etched to reveal indium tin oxide (ITO) front contacts. Once the cell is cooled, the surface of the cadmium sulfide layer is etched or scribed. Once the cell is cooled, material is deposited onto the device to create rear contacts. Etching to reveal the ITO contacts is carried out using a bromine methanol solution. The etching is carried out by the use of a pressurized water spray. The etching takes place at 100degreesC. When etching to reveal the ITO contacts, the bromine methanol solution is bromine solution (2%). The etching of the cadmium telluride layer is carried out using bromine solution (0.26%) applied for 5 seconds to remove around 1 microns of the cadmium telluride layer. The rear contact involves depositing metallic material on the cap layer or an etched region of the cap layer. The rear contact has a thickness of 0.005-1 microns. The back contact material is evaporated from a wire formed from material. The evaporation is achieved using a tungsten coil in a vacuum of around 2x10-5 Torr. The evaporation takes place at room temperature to 100degreesC. The layer of transparent conductive oxide (102) (TCO) on the cell is provided between the superstrate and the window layer. The layer of transparent conductive oxide (TCO) on the cell is provided over the window layer. The metal organic chemical vapor deposition (MOCVD) is used to grow a layer of transparent conductive oxide on the cell. The MOCVD is used to grow a multilayer graded band gap between the window layer and the absorber layer. The annealing process involves maintaining the cell at 240-520 (preferably 400)degreesC and for 5 minutes to 1 hour (preferably 10) minutes under hydrogen. The annealing process takes place after a stabilization period of 1-10 (preferably 5) minutes. The annealing process takes place under an inert gas, a reactive gas or a mixture of gases. The cap layer formation and annealing are performed simultaneously. The MOCVD is used to grow a high resistivity layer (103) on the cell provided between the transparent conductive oxide (TCO) layer and the window layer. The MOCVD is used to grow an additional highly p+ doped layer of p+ type material on the cell. The highly p+ doped layer is provided between the absorber layer and the cap layer if the cell is formed on a superstrate and is provided between the absorber layer and the substrate if the cell is formed on a substrate. The MOCVD is used to grow a layer of arsenicAs-doped cadmium telluride:As(+). The MOCVD is used to grow a layer of low band gap material. The layer of low band gap material is provided between the absorber layer and the cap layer. The layer of low band gap material is provided between the highly p+ doped layer and the cap layer with a highly p+ doped layer. The low band gap layer is grown at a substrate temperature of 280-460 (preferably 320-400, especially 390)degreesC. The layer is grown at a gas flow rate of 1000-10000 (preferably 4400) sccm. The front contact (104) comprises indium tin oxide. Preferred Cell: The cell (A1) and (A2) further comprises cadmium telluride absorber layer which is alloyed with zinc; a layer of transparent conductive oxide (TCO); high resistivity layer; highly p+ doped layer of p+ type material; and cadmium chloride cap layer. In the cell (A1) and (A2), the doping is even throughout the absorber layer. The doping is graded over the absorber layer. The doping is concentrated at particular places along the absorber layer. The cell (a1) and (A2) are formed on a substrate or superstrate (where substrate or superstrate has a patterned contact layer.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The cadmium sulfide window layer has thickness of 0.24 microns. The cadmium sulfide window layer is alloyed with zinc. The concentration of arsenic in the absorber layer is 1x10+17-2x10+19 (preferably 2x10+18) atomsphere/cm3. The absorber layer has thickness of 0.6-5 (preferably 4-5) microns. The II:VI precursor ratio of the absorber layer is 1.82. The cap layer has thickness of 0.05-1 (preferably 0.45) microns. The II:VII precursor ratio of the cap layer is 0.29. The material deposited to create the rear contacts is gold, molybdenum, nickel or an alloy or mixture of gold, molybdenum or nickel. The TCO layer comprises cadmium stannate, cadmium oxide or doped tin oxide. The multilayer graded band gap comprises cadmium selenide multilayer. The cadmium selenide multilayer is grown from dimethylcadmium and dimethylselenide organo-metallic precursors. The cadmium selenide multilayer is grown at a substrate temperature of 240-410 (preferably 320-400, especially 350degreesC. The cadmium selenide multilayer is grown at a cadmium partial pressure of 1x10-5-1\%10-2 (preferably 1x10-4-1x10-3, especially 2x10-4) atmospheres. The cadmium selenide multilayer has a thickness of 0.02-2 microns. The high resistivity layer comprises zinc Stannate, zinc oxide or zinc sulfide. The highly p+ doped layer comprises ZnTe:As, ZnTe:N, or binary/tertiary alloys based upon Cd(Zn)Te. The binary/tertiary alloys based upon Cd(Zn)Te are doped with As or other group V or p-type donor to increase acceptor concentration. The highly p+ doped layer of doped Cd(Zn)Te absorber layer is grown from dimethylcadmium, diethylzinc (or dimethylzinc), diisopropyltelluride and tris(dimethylamino)arsine organo-metallic precursors. The highly p+ doped layer is grown at a substrate temperature of 280-460 (preferably 350-420, especially 390)degreesC. The highly p+ doped layer is grown at a total gas flow in the reactor of 1000-10000 sccm. The highly p+ doped layer is grown at a total gas flow in the reactor of 4500 sccm. The highly p+ doped layer is grown at a cadmium partial pressure of 1x10-5-1\%10-2 (preferably 1x10-4-1x10-3) atmospheres. The highly p+ doped layer is grown at cadmium partial pressure of 2x10-4 atmospheres. The cadmium selenide multilayer is grown at a arsenic partial pressure of 1x10-10-1x10-4 (preferably 1x10-7-8x10-6, especially 1.5x10-6) atmospheres. The concentration of arsenic in the highly p+ doped layer is 1x10+17-5x10+19 (preferably 1.5x10+18) atomsphere/cm3. The highly p+ doped layer of doped Cd(Zn)Te absorber layer is grown at an arsenic partial pressure of 1x10-10-1x10-4 atmospheres. The highly p+ doped layer has a thickness of 0.05-1.5 (preferably 0.25) microns. The layer of arsenic-doped cadmium telluride:As(+) acts as a highly p+ doped layer. The layer of arsenic-doped cadmium telluride:As(+) has an arsenic concentration of 1x10-5x10 atomosphere/cm3. The layer of arsenic-doped cadmium telluride:As(+) has a thickness of 0.05-0.5 microns. The low band gap layer comprises As2Te3. The low band gap layer is grown from tris(dimethylamino)arsine and diisopropyltelluride organo-metallic precursors. The low band gap layer comprises Sb2Te3. The low band gap layer is grown from trismethylantimony and diisopropyltelluride organo-metallic precursors. The low band gap layer is grown at an arsenic partial pressure of 1x10-10-1x10-2 (preferably 1x10-7-1x10-4) atmospheres. The low band gap layer is grown at an arsenic partial pressure of 5x10-5 atmospheres. The low band gap layer is grown at antimony partial pressure of 1x10-10-1x10-2 (preferably 1x10-7-1x10-4) atmospheres. The low band gap layer is grown at antimony partial pressure of 5x10-5 atmospheres. The low band gap layer has a thickness of 0.02-1 (preferably 0.1) microns.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The metal organic chemical vapor deposition (MOCVD) reactor is a horizontal MOCVD reactor or a vertical MOCVD reactor. The heat source in the MOCVD reactor is a resistive heat source. The heat source in the MOCVD reactor is a radiation emission source.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The precursor is alkyl and/or other volatile chemicals which can crack bond by pyrolysis, photocatalysis, microwave, plasma. The carrier gas is hydrogen, nitrogen, inert gas and/or a reactive gas. The cap layer is grown by use of an alkyl chloride precursor such as n-hexylchloride or tertiarybutylchloride.