Fabrication of AgGaTe2Solar Cells Using GaTe Powder to Suppress Mo–Te Compounds Formation near the Electrode Layer

Abstract

AgGaTe2is an attractive material for the light‐absorbing layer in solar cells and has been deposited by close‐spaced sublimation using Ga2Te3powder source. However, the samples exhibit an excess of Te, as well as undesired Mo–Te compounds, when AgGaTe2is deposited on Mo/glass substrates. Therefore, the AgGaTe2light‐absorbing layer is deposited using an Ag2Te and GaTe mixed powder source and examined herein. By replacing the Ga2Te3source with GaTe, the Te content confirmed by the X‐ray fluorescent has significantly decreased. Cross‐sectional transmission electron microscopy observation indicates that the formation of Mo–Te compounds is suppressed. This is because Ga2Te3produces additional Te gas in the initial decomposition reaction during deposition, and GaTe does not. In addition, theJ–Vcurves show an improved conversion efficiency for solar cells fabricated using GaTe.