TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The CIGS solar cell further comprises: the bottom electrode layer located between the glass substrate and the photoelectric transducer structure, where the bottom electrode layer is made of a metal or non-metallic oxide; the intermediate layer or sodium-compound layer located between the photoelectric transducer structure and the bottom electrode layer; the top electrode layer located on the photoelectric transducer structure; the wire located on the top electrode layer; and the anti-reflection layer located on the wire. The predetermined depth is greater than or equal to 1 mm. The p-type semiconductor layer comprises copper oxide and aluminum oxide. The arrayed protrusions are: equally spaced at 0.625 mm; and pillar-shaped, preferably cylinders. Preferred Method: The step of forming the arrayed protrusions comprises: coating a protective film onto the surface of the glass substrate; soaking the glass substrate in an etchant, taking out the glass substrate after a predetermined time, and then rinsing the glass substrate; and removing the protective film from the glass substrate. The method further comprises: forming the sodium-compound layer between the bottom electrode layer and the photoelectric transducer structure. The n-type semiconductor layer is formed by heating a precursor compound film and a second precursor compound film in a VIA Group gas atmosphere. The first precursor compound film and the second precursor compound film are formed by electro-deposition, electroless-deposition, atomic layer deposition, chemical vapor deposition, metal-organic chemical vapor deposition or physical vapor deposition. The heating of the first precursor compound film and the second precursor compound film comprises: activating an excitation source for activating the VIA Group gas, where the excitation source is activated by an electron beam device, an ion beam device, a plasma resonance device or a pyrolysis device. The temperature of heating the first precursor compound film and the second precursor compound film is 380-600 degrees C.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal is titanium, molybdenum, tantalum or their alloys. The intermediate layer is made of tin, tellurium or lead. The CIGS compound comprises the first precursor compound and the second precursor compound, where the first precursor compound comprises copper, gallium and selenium, and the second precursor compound comprises indium and selenium. The CIGS compound is of formula Sn:Cu(In1-xGax)Se2.x = 0.18-0.3. EXAMPLE - No suitable example given.