Enhanced infrared transmission of GZO film by rapid thermal annealing for Si thin film solar cells

Ga doped ZnO (GZO) films prepared by sputtering at room temperature were rapid thermal annealed (RTA) at elevated temperatures. With increasing annealing temperature up to 570°C, film transmission enhanced significantly over wide spectral range especially in infrared region. Hall effect measurements revealed that carrier density decreased from ∼8 × 10²⁰ to ∼ 3 × 10²⁰ cm⁻³ while carrier mobility increased from ∼15 to ∼28 cm²/Vs after the annealing, and consequently low film resistivity was preserved. Hydrogenated microcrystalline Si (µc‐Si:H) and microcrystalline Si_1‐xGe_x (µc‐Si_1‐xGe_x:H, x = 0.1) thin film solar cells fabricated on textured RTA‐treated GZO substrates demonstrated strong enhancement in short‐circuit current density due to improved spectral response, exhibiting quite high conversion efficiencies of 9.5% and 8.2% for µc‐Si:H and µc‐Si_0.9Ge_0.1:H solar cells, respectively. Copyright © 2011 John Wiley & Sons, Ltd.