TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compositions: Weight ratio of Cu/(In+Ga) is 0.6-0.95 or 0.85, and Ga/(In+Ga) is 0.2-0.42 or 0.31. Preferred Process: Preparation of porous and absorbent layer is performed by melting Cu and Ga in vacuum induction smelting furnace at 650 degrees C with vacuum pressure of 5x 10-2 torr for 15 minutes, casting in 3 inches low carbon steel mold, cooling for 12 hours, removing blank, processing to 3-inch CuGa target, melting In material in vacuum induction melting furnace with vacuum pressure of 5x 10-2 torr and melting temperature of 200 degrees C for 15 minutes, casting in 3 inches low carbon steel mold, cooling for 12 hours, removing blank, processing to 3-inch In target, placing alkali-free glass substrate, substrate coating material, CuGa target and In target in sputtering chamber using argon gas as working gas with vacuum pumping system which maintains chamber background pressure to 0.7x 10-5-0.9x 10-5 torr, preferably 0.8x 10-5 and throttle valve control to introduce argon gas, sputtering molybdenum using direct current power at chamber working pressure of 2x 10-3 and plating rate of 40 nm/minute to obtain thin film with 500 nm thickness, sputtering CIG at chamber working pressure of 20x 10-3-30x 10-3 torr, preferably 25x 10-3 and plating rate of 2-6 nm/minute, preferably 4 nm/minute to obtain absorbing layer with 1000 nm thickness, plating with selenium using selenide plating furnace at 500-650 degrees C, preferably 620 degrees C for 10-30 minutes, preferably 20 minutes to obtain selenide film with thickness of 1950-2050 nm, preferably 2000 nm and removing test piece. Preparation of porous and absorbent layer is performed by melting Cu, In, and Ga material in vacuum induction smelting furnace at 650 degrees C with vacuum pressure of 5x 10-2 torr for 15 minutes, cooling for 12 hours, removing blank, processing to 3-inch CuInGa target, placing alkali-free glass substrate, substrate coating material, and CuInGa target in sputtering chamber using argon gas as working gas with vacuum pumping system which maintains chamber background pressure to 0.7x 10-5-0.9x 10-5 torr, preferably 0.8x 10-5 torr and throttle valve control to introduce argon gas, sputtering molybdenum using direct current power at chamber working pressure of 2x 10-3 and plating rate of 40 nm/minute to obtain thin film with 500 nm thickness, sputtering CIG at chamber working pressure of 20x 10-3-30x 10-3 torr, preferably 25x 10-3 torr and plating rate of 2-6 nm/minute, preferably 4 nm/minute to obtain absorbing layer with 1000 nm thickness, plating with selenium using selenide plating furnace at 500-650 degrees C, preferably 620 degrees C for 10-30 minutes, preferably 20 minutes to obtain selenide film with thickness of 1950-2050 nm, preferably 2000 nm and removing test piece.