Transparent conducting oxides at high aspect ratios by ALD

Transparent conducting oxides (TCOs) are important electronic materials which as their name implies possess the seemingly mutually exclusive properties of high optical transmittance in the visible region (>80%) and relatively high conductivity. These properties are achieved with high carrier mobilities in relatively wide band gap n-type semiconductor materials. TCOs are sensitive to composition and oxygen stoichiometry. Atomic Layer Deposition (ALD) is an ideal deposition method, particularly when high aspect ratio materials must being coated. Here we use exposure times to control the deposition area. Very long exposure times are used to coat high aspect ratio pores uniformly while short exposure times are used to produce pore closing outer surface films. copyright The Electrochemical Society.