Growth and Characterization of an In-based Buffer Layer by CBD for Cu(In,Ga)Se[sub 2] Solar Cells

An In-based buffer layer was deposited by using the chemical bath deposition (CBD) technique from the acetic aqueous solution containing and and its structure and optical properties have been characterized. and InOOH phases were found in the buffer layer from the combined results of X-ray photoelectron spectra and X-ray diffraction patterns. The growth of InOOH through the chemical bath deposition has not been previously reported. The compositional ratio of and InOOH in the film was ∼3. The Auger In MNN peak and the direct band gap of the InOOH phase are 407.1 and 3.5 eV, respectively. A uniform 30 nm thick film with a tightly connected grain structure was grown by the chemical bath deposition process. The optical transmittance of the buffer layer was higher than that of CdS buffer layer, due to an indirect band gap of suggesting that this new film is a good candidate for the buffer layer of solar cells.