Electrodeposition of In₂Se₃ Using Potential Pulse Atomic Layer Deposition

Abstract

Indium(III) selenide, In 2 Se 3 , thin films were electrodeposited at room temperature from an aqueous solution containing ionic precursors for both In and Se, using potential pulse atomic layer deposition (PP-ALD). Cyclic voltammetry was used to determine approximate cycle potentials, and anodic and cathodic potentials were systematically examined to optimize the potential pulse program for In 2 Se 3 . Electron probe microanalysis was used to follow the In:Se atomic ratio as a function of the cycle conditions, and annealing studies were performed on stoichiometric deposits. Film thickness was a function of both the anodic and cathodic potentials. The optimum growth rate was consistent with previous PP-ALD studies in which similar concentrations and pulse times were employed, 0.02 nm/cycle. The use of the potential pulse cycle for film growth resulted in surface-limited control over the deposit stoichiometry each cycle and thus a layer-by-layer growth process.

Electrochemical Atomic Layer Deposition of CuInSe2 on Au Surface

“…The cathodic peak current observed between −0.1 and −0.2 V at the scan rates from 10 to 100 mV/s depended almost linearly on the scan rate as is shown in the inset of the Figure , suggesting that the pair of the cathodic and anodic peaks originate from the surface processes or In UPD and stripping of it. The present result is the first observation of In UPD process at the surface of Au electrode . The deposition potentials from −0.56 to −0.50 V were selected on the basis of the CV in Figure , which is much less negative than that, −0.7 V, employed in the previous reports …”

“…Unlike the cases of Cu and Se, electrochemistry of In is rather less well defined in the literature 31,[34][35][36][37][38]41,42 and is presented here. Figure 1 shows the CV at the surface of the Au electrode in an aqueous electrolyte solution of 0.5 mM In 2 (SO 4 ) 3 •xH 2 O and 0.1 M NaClO 4 solution at pH 3.…”

“…The present result is the first observation of In UPD process at the surface of Au electrode. 31,[34][35][36][37][38]41,42 The deposition potentials from −0.56 to −0.50 V were selected on the basis of the CV in Figure 1, which is much less negative than that, −0.7 V, employed in the previous reports. 34,35,38 The potentials chosen in this experiment were different from those by Stickney et al and optimized to produce the stoichiometric film within the potential range mentioned in the above.…”

“…A handful of semiconductor compounds have been synthesized by E‐ALD techniques, including CIS and CIGS . Wang et al .…”

“…The deposition can be also performed as p number of cycles of a certain compound (for example, InSe) and alternate q number of cycles of another compound (for example, Cu 2 Se), called superlattice program, and this process can be repeated to produce the target quantity film. [22][23][24] A handful of semiconductor compounds [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] have been synthesized by E-ALD techniques, including CIS 33,34 and CIGS. 35,36 Wang et al have deposited CIS on a flexible, carboxyl-functionalized multi-walled carbon nanotube/polyimide (COOH-MWCNT/PI) nanocomposite membrane 33 and Stickney et al have reported CIS on Au surfaces.…”