NOVELTY - A thin film solar cell (10) comprises a substrate (11), a front electrode layer (12), a photoelectric conversion layer, a rear electrode layer (15) stacked in such sequence, and an interlayer (13) disposed between the front electrode layer and a absorber layer (14), where the interlayer has p-type holes formed by introducing a nitrogen-based gas containing argon (Ar) as a carrier gas interacted with the group III element so that the concentration of nitrogen atoms in the interlayer is greater than 1015/cm3.    USE - As a thin film solar cell (claimed).    ADVANTAGE - The thin film solar cell has enhanced open-circuit voltage. The method forms the p-type interlayer on the front electrode layer so as to restrain the damage to the transparent conductive oxide (TCO) surface, and prevents damage to the TCO surface from hydrogen plasma generated by plasma-enhanced chemical vapor deposition (PECVD) used for manufacturing the absorber layer; producing the p-type TCO at simplified manner; and improves the mass production of thin film solar cell.    DETAILED DESCRIPTION - A thin film solar cell (10) comprises a substrate (11), a front electrode layer (12), a photoelectric conversion layer, a rear elecaztrode layer (15) stacked in such sequence, and an interlayer (13) disposed between the front electrode layer and a absorber layer (14), where the interlayer has p-type holes formed by introducing a nitrogen-based gas containing argon (Ar) as a carrier gas interacted with the group III element so that the concentration of nitrogen atoms in the interlayer is greater than 1015/cm3, and where the front electrode layer is formed by doping group III element into a zinc oxide. The nitrogen-based gas is nitric oxide, nitrous oxide, nitrogen dioxide, ammonia, and N2. The interlayer comprises nitrogen, oxygen, hydrogen, and compound of nitrogen and binary or ternary compound of group III element. The compound of nitrogen and group III element is aluminum nitride (Al-N) or gallium nitride (Ga-N). The group III element is selected from aluminum (Al), gallium (Ga), indium (In), and boron (B). The front electrode layer is selected from aluminum-doped zinc oxide (AZO), Ga-doped ZnO, B-doped ZnO (BZO), and indium zinc oxide (IZO). The metal is selected from silver (Ag), Al, titanium silver alloy, and titanium aluminum alloy. An INDEPENDENT CLAIM is included for manufacturing a thin film solar cell involving providing a substrate; depositing a front electrode layer on a top of the substrate, where the front electrode layer is formed by doping group III element into a zinc oxide; depositing an interlayer on the front electrode layer, where the interlayer is formed by introducing a nitrogen-based gas containing argon (Ar) as a carrier gas interacted with the group III element by using plasma enhanced chemical vapor deposition or thermal treatment, implementation and diffusion on the front electrode layer surface so that the concentration of nitrogen atoms in the interlayer is greater than 1015/cm3; depositing an absorber layer on the interlayer; and depositing a rear electrode layer on the absorber layer.    DESCRIPTION OF DRAWING(S) - The figure shows view of thin film solar cell.    Thin film solar cell (10)    Substrate (11)    Front electrode layer (12)    Interlayer (13)    Absorber layer (14)