Structural and electric properties of AgGaTe₂ layers prepared using mixed source of Ag₂Te and Ga₂Te₃

AgGaTe₂ layers were prepared on Si substrates by a closed space sublimation method using a mixed powder source of Ag₂Te and Ga₂Te₃. Ag₂Te buffer layer deposition was introduced to eliminate melt-back etching. The effect of the molar ratio of Ag₂Te and Ga₂Te₃ in the mixed source on the crystallinity of the AgGaTe₂ layer was investigated. The composition and the phase of the layer was found to change depending on the molar ratio in the deposits, which could be controlled by the source molar ratio along with the Ag₂Te buffer layer thickness. It was confirmed that (112) oriented uniform AgGaTe₂ layer with an abrupt interface between AgGaTe₂ and Si was formed after those parameters were tuned. The obtained layer exhibited the acceptor concentration of around 2.5 × 10¹⁶ cm⁻³. A solar cell was fabricated using the p-AgGaTe₂/n-Si heterojunction, and exhibited a conversion efficiency of 1.15%.