TECHNOLOGY FOCUS - ELECTRONICS - Preferred Component: A mechanism is included for providing in sequence a substrate to reactor zones for preparing the substrate. A first processing zone is capable of providing an environment for transition of the substrate from an ambient environment to the processing environment. The substrate transitions, in part or whole, from atmospheric pressure to reduced pressure consistent with the subsequent processing environment. A processing zone is capable of providing an environment for deposition of a barrier layer (110). The barrier layer comprises a thin conductor or very thin insulating material. A processing zone is capable of providing an environment for deposition of a conductive back contact layer (120). Deposition of a conductive back contact layer comprises a metallic layer. A processing zone is capable of providing an environment for deposition of alkali materials (140). A processing zone is provided capable of providing an environment for deposition of a semiconductor layer. A processing zone is capable of providing an environment for deposition of an additional semiconductor layer (130) wherein the semiconductor layer comprises precursor p-type absorber materials. A processing zone is capable of providing an environment for thermal treatment of layers. The treatment occurs in the pressure range of 10-6 torr up to atmospheric pressure and temperature range of 300-00degreesC. The n-type semiconductor layer is formed by diffusion of a dopant species into a p-type absorber layer. A processing zone is provided capable of providing an environment for deposition of an insulating transparent semiconductor layer (150). A processing zone is capable of providing an environment for deposition of a conducting transparent semiconductor layer.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The metallic layer comprises conductive metals from molybdenum (preferably), titanium, tantalum, or other acceptable metals or alloys. The alkali materials are Na-VII or Na2-VII. The semiconductor layer comprises Group I, III, VI elements. The semiconductor layer comprises CuGaSe2, CuAlSe2, or CuInSe2 alloyed with I, III, VI elements. The precursor materials comprise Group I, III, VI elements; I-(IIIa, IIIb)-VI2 layer; or I-(IIIa, IIIb)-VI2 layer where the IIIb/(IIIa+IIIb) is greater than to less than O.4. The semiconductor layer comprises a CIGS absorber layer comprising In1- xGaxSe2 where x is 0.2-0.3 where the thickness ranges from about 1-3 microns. The absorber layer is formed by the delivery of type I, III and VI precursor metals where Cu, In1-x, Ga, and Se2 layers are sequentially deposited on the substrate (105). The Cu:Gax layer is formed by the delivery of the type I, III and VI precursor metals where Cu, In1-x, Ga, and Se2 layer are sequentially deposited on the substrate and then synthesized into an alloy mixture with a thermal treatment. The absorber layer is formed by the delivery of type I, III and VI precursor metals where Cu:Gax layer is separately synthesized, and then co-deposited with an In1 layer and Se2 layer on a substrate, and synthesized into an alloy mixture with a thermal treatment. The discrete layer comprises one or more of Group II-VI, III-VI elements. The discrete layer materials comprise (In,Ga)(Se,S,O) and (Zn,Cd) (Se,SO), or (In,Ga)2Se3, (In,Ga)2S3, ZnSe, ZnS, and ZnO. The dopant species is Group II or III elements, preferably zinc or cadmium. The insulating transparent semiconductor layer comprises materials from Group II-VI or II-IV-VI, preferably zinc oxide or indium tin oxide. The conducting transparent semiconductor layer comprises Group II-VI or II-IV-VI, preferably zinc oxide, cadmium tin oxide, or indium tin oxide.