Effect of oxygen intercalation on properties of sputtered CuYO2 for potential use as p-type transparent conducting films

Abstract

Transparent films of copper yttrium oxide doped with 2% calcium have been prepared by rf magnetron sputtering. The films show a conductivity of 8 Scm -1 on intercalation of oxygen at high pressure, which reduced the transparency in the visible region. The Ca-doped CuYO 2 films before oxygen intercalation show an average transmission of about 60% which reduces to about 45% upon oxygen intercalation. The temperature dependence of the conductivity indicates semiconductor behaviour with low activation energy of 0⋅59 eV at room temperature. The positive sign of Seebeck coefficient (+274 μVK -1 ) confirms the p-type conductivity of the films. The optical bandgap of CuYO 2 was found to be 3⋅15 eV.

Transparent Electrodes for Efficient Optoelectronics

“…[61] With a free carrier density of holes of N h = 1.3 × 10 17 cm −3 and a hole mobility at ≈10 cm 2 V −1 s −1 , the conductivity (<1 S cm −1 ) was much lower than of n-type TCOs. Subsequently, other Cu-based delafossites with Al replaced by other metal cations, such as Cr, [62] Fe, [63] Sc, [64] and Y, [65] were investigated with oxygen intercalation and various synthesis methods (and thus, various microstructures) with the aim of decreasing the dopant compensation and increasing mobility (Figure 1). Recently, the CuCrO 2 has been explored with promising results; Mg-doped CuCrO 2 has the highest p-type conductivity reported for an oxide to date, 220 S cm −1 .…”

P‐Type Transparent Cu‐Alloyed ZnS Deposited at Room Temperature

“…Table S1 in the SI. [14,19,21,22,27,28,34,51,[60][61][62] The y-axis is the highest temperature reached during synthesis (either deposition or annealing). The color scale represents increasing absorption coefficient (averaged over 400 -800 nm), with white the lowest (most transparent) and blue the highest (least transparent).…”

“…Many oxides have been investigated including oxygen intercalated and doped Cu-delafossites with Al replaced by other metal cations such as Cr, [19] Fe, [20] Sc, [21] and Y, [22] ZnO-based TCOs such as N:In co-doped ZnO, [23] spinel structure TCOs such as NiCo 2 O 4, [24,25] and amorphous oxides such as ZnO·Rh 2 O 3 and MoO 3 . [26,27] However, the performance of p-TCMs remains inferior by orders of magnitude compared to that of n-TCMs.…”

“…Table S1). [14,[19][20][21][22]32,51] Outside of the TCM regime, for example in the x = 0.45 sample, conductivity decreases by nearly three orders of magnitude at low temperatures, indicating an activated transport mechanism with low conductivity at room temperature (0.25 S cm -1 ).…”

Transparent Conducting Oxides—An Up-To-Date Overview

“…As further metal, A, iron [143,144,145], cobalt [138] or chrome [146,147,148,149,150] (without doping hardly transparent) may be used as well as elements of the 2nd group of the periodic table of the elements—strontium [151,152,153,154], barium [155]—or the 3rd group—aluminum [149,156,157,158,159,160,161,162,163,164,165,166,167,168,169], gallium [168,169], indium [170], scandium [171,172], yttrium [173,174,175,176], lanthanum [175,176]. Moreover, other lanthanides such as praseodymium, neodymium samarium and europium have been applied [175,176,177], in order to get ternary semiconductor compounds.…”