TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The first buffer layer is ALD deposited Zn(Ox,S1-x).x=varies between 0-0.9, preferably between 0.1-0.7.The first buffer layer comprises hydrogen, where the zinc compound comprises zinc hydroxide. The first buffer layer is ALD deposited indium sulfide (In2S3). Preferred Dimension: The thickness of the first buffer layer is larger than 1 nm, and less than 30 nm. Preferred Method: Providing the first sulfur containing buffer layer comprises exposing the absorbing layer in the ALD reaction chamber alternatively, to pulses of a organo metallic zinc compound such as diethyl zinc or dimethyl zinc, to form a zinc containing monolayer, and to alternate pulses of water and hydrogen sulfide (H2S), to grow oxygen and sulfur on the zinc atoms, to form a first monolayer, which is adsorbed on top of the light absorbing layer, repeating the steps to grow additional sulfur containing monolayers layers on top of each other, and continuing this process until the first sulfur containing buffer layer of a first predefined thickness is obtained. The method comprises providing the second ZnO buffer layer in the same way as the first buffer layer leaving out the pulses of H2S, by continuing to expose the first buffer layer in the ALD reaction chamber alternatively to gas pulses of an organo metallic zinc compound, and pulses of water until the second ZnO buffer layer of a second predefined thickness is obtained; and successively decreasing the proportion of sulfur as the additional monolayers are grown, to obtain a soft transition of the first buffer layer into the second buffer layer. Preferred Parameter: There is a graded transition of the first buffer layer into the second buffer layer, the sulfur content of the first buffer layer gradually decreasing in a direction over its thickness. Pulses of H2S are provided in a proportion of 10-100, preferably 15-25, more preferably 20%, of the total number water- and H2S pulses.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The first buffer layer is ALD deposited Zn(Ox,S1-x).x=varies between 0-0.9, preferably between 0.1-0.7.The first buffer layer comprises hydrogen, where the zinc compound comprises zinc hydroxide. The first buffer layer is ALD deposited indium sulfide (In2S3). Preferred Dimension: The thickness of the first buffer layer is larger than 1 nm, and less than 30 nm. Preferred Method: Providing the first sulfur containing buffer layer comprises exposing the absorbing layer in the ALD reaction chamber alternatively, to pulses of a organo metallic zinc compound such as diethyl zinc or dimethyl zinc, to form a zinc containing monolayer, and to alternate pulses of water and hydrogen sulfide (H2S), to grow oxygen and sulfur on the zinc atoms, to form a first monolayer, which is adsorbed on top of the light absorbing layer, repeating the steps to grow additional sulfur containing monolayers layers on top of each other, and continuing this process until the first sulfur containing buffer layer of a first predefined thickness is obtained. The method comprises providing the second ZnO buffer layer in the same way as the first buffer layer leaving out the pulses of H2S, by continuing to expose the first buffer layer in the ALD reaction chamber alternatively to gas pulses of an organo metallic zinc compound, and pulses of water until the second ZnO buffer layer of a second predefined thickness is obtained; and successively decreasing the proportion of sulfur as the additional monolayers are grown, to obtain a soft transition of the first buffer layer into the second buffer layer. Preferred Parameter: There is a graded transition of the first buffer layer into the second buffer layer, the sulfur content of the first buffer layer gradually decreasing in a direction over its thickness. Pulses of H2S are provided in a proportion of 10-100, preferably 15-25, more preferably 20%, of the total number water- and H2S pulses.