Non-equilibrium deposition of phase pure Cu2O thin films at reduced growth temperature

Abstract

Cuprous oxide (Cu2O) is actively studied as a prototypical material for energy conversion and electronic applications. Here we reduce the growth temperature of phase pure Cu2O thin films to 300 °C by intentionally controlling solely the kinetic parameter (total chamber pressure, Ptot) at fixed thermodynamic condition (0.25 mTorr pO2). A strong non-monotonic effect of Ptot on Cu-O phase formation is found using high-throughput combinatorial-pulsed laser deposition. This discovery creates new opportunities for the growth of Cu2O devices with low thermal budget and illustrates the importance of kinetic effects for the synthesis of metastable materials with useful properties.

Ion implantation induced phase transformation and enhanced crystallinity of as deposited copper oxide thin films by pulsed laser deposition

“…At higher oxygen pressure, the Cu-O phase diagram reflects formation of both Cu 2 O and CuO phases during oxidation [25]. In our investigation, no crystalline phase of copper oxide was formed at 80 mTorr while Cu 2 O was formed as the major component in the thin film fabricated at 100 mTorr partial pressure of oxygen, and the results are consistent with recent studies [26].…”

Combinatorial insights into doping control and transport properties of zinc tin nitride

“…A growth temperature gradient was induced perpendicular to the cation composition gradient by contacting the substrate on one end with a heated metal pad. 21 Hot-side set point temperatures were 110 • C, 220 • C, 330 • C, and 400 • C, which provided an overall spread in growth temperature from 340 • C to 60 • C. Actual growth temperatures achieved were calibrated by placing a thermocouple in contact with the substrate surface at four representative regions (along the decreasing temperature gradient and spaced 12.5 mm apart) for each of the hot-side temperatures mentioned. Additionally, a sample was grown with no active heating of the substrate, and was calibrated by thermocouple to be at 35 • C as a result of sputtered particle impingement on the substrate surface during growth.…”

Design of Semiconducting TetrahedralMn1−xZnxOAlloys and Their Application to Solar Water Splitting

“…The combinatorial synthesis and characterization approach [20,21] was used to deposit Mn 1−x Zn x O thinfilm "libraries" with both a composition [22] and a temperature [23] gradient. The samples of the present work were grown by PLD from MnO and ZnO targets in the temperature range 180°C ≤ T ≤ 520°C, spanning a wide composition range of about 0.05 ≤ x ≤ 0.75, which extends to both sides of the predicted critical composition for the structural transition.…”

“…We employed a thin-film highthroughput combinatorial approach [20,21] to deposit "libraries" with a spatial gradient in both the composition [22] and the substrate temperature [23], using commercial 2-inch targets (purity 99.99%) of MnO, ZnO, and 4% Ga-doped ZnO. A calibration process was performed to express the substrate temperature as a function of the position on the substrate and the set-point temperature [23]. The laser was operated at 40 Hz, and the beam was focused through a 60-cm lens onto the rotating targets at a 45°a ngle, with a laser fluence of 4 J=cm 2 on the target surface.…”