NOVELTY - Deposition of a semiconductor layer on a substrate (145) comprises sputtering a material from a target onto a substrate to provide a semiconductor layer, while simultaneously doping and/or alloying the semiconductor layer with a metal organic precursor.    USE - The method is for deposition of a semiconductor layer on a substrate to prepare a product i.e. gallium-doped zinc oxide (GZO) layer having a refractive index of less than 1.80, as measured at a wavelength of 600 nm, doped zinc oxide layer comprising aluminum and/or gallium, zinc oxide layer alloyed with magnesium and/or cadmium, or doped and/or alloyed zinc oxide layer having a single crystalline orientation (claimed) or polycrystalline orientation. It is useful for preparing co-doped aluminum-gallium-doped zinc oxide (AGZO) layer. Uses include but are not limited to solar cells (e.g. copper indium gallium diselenide (CIGS) solar cells), photovoltaic modules, bandpass filters, light dispersion gratings, reflective diffraction gratings, transmissive diffraction gratings, and distributed Bragg reflectors.    ADVANTAGE - The method provides a physical deposition process (i.e. sputtering) that is more flexible, more cost effective, and less complicated than current deposition techniques. It permits in-situ composition control for doped and/or alloyed thin films, and permits facile control over varying the composition of doped and/or alloyed thin films that are used in multilayer devices. The method reduces or eliminates the need for using multiple sputtering targets, or for designing and implementing sputtering targets having a doped composition, to deposit doped and/or alloyed films. The transparent conductive oxide (TCO) layer can be deposited onto an underlying CIGS solar cell, without damaging the underlying layers of the cell. The use of textured TCO layer with CIGS solar cell can reduce reflection of incident light compared to smooth TCO layers deposited using other methods. The method is suitable for depositing doped zinc oxide layer that is environmentally stable. Dopant and/or alloy concentration in zinc oxide layer can be adjusted to optimize the temperature stability and moisture stability of a layer, while retaining a low resistivity. The aluminum-doped zinc oxide layer is stable in humid and/or moist environment. The method provides AGZO layer having optimized electrical properties and superior stability. The doped and/or alloyed semiconductor layer improves light trapping in solar cell.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a product prepared by a method of depositing a semiconductor layer on a substrate (145); and    (2) deposition apparatus (100) comprising a deposition chamber that includes a surface that includes a target material (101); a cathode assembly for supporting the surface that includes the target material; mechanism for sputtering the target material from the surface; gas source (110); metal organic precursor source (130); and mechanism for positioning a substrate a distance from the surface.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic cross-sectional view of a portion of deposition apparatus.    Deposition apparatus (100)    Target material (101)    Plasma (102)    Gas source (110)    Metal organic precursor source (130)    Substrate (145)