Nucleation and growth kinetics of co-deposited copper and selenium precursors to form metastable copper selenides

The role of interparticle heterogeneities in the selenization pathway of Cu–Zn–Sn–S nanoparticle thin films: a real-time study

“…2a-f, the relative intensity of the CuSe peaks from the 102 and 006 crystal planes is different for the small particle sample than for the large and mixed precursor films, indicating the CuSe grains grow with a preferred texture in the absence of the large, Zn-rich particles based on the expected relative peak intensities for hexagonal CuSe. 39,40 In the small particle sample, CuSe quickly vanishes near 350 °C while a strong Cu2-δSe signal appears (Fig. 2c), suggesting CuSe undergoes a transition to Cu2-δSe wherein Cu is reduced and Se is liberated from the crystal lattice; this transition has similarly been observed for co-evaporated Cu-Se films (albeit at a slightly higher temperature of 377 °C), in which the liberated Se manifests as a liquid phase.…”

“…During slow heating, peaks corresponding to the 102 and 006 planes in hexagonal CuSe 39,40 are observed for all three samples between ~225 and ~350 °C. A third peak attributed to the 101 planes in hexagonal CuSe is observed when slow heating the small particle sample within the same temperature range (Fig.…”

Defect visualization of Cu(InGa)(SeS)2 thin films using DLTS measurement

“…The Cu 9 Ga 4 alloy remained at the bottom of the absorber layer because of partial selenization at low temperatures and then started to melt at approximately 490 °C in the inert gas condition. The Cu 9 Ga 4 alloy was then present in the liquid phase, allowing grains to grow through the mechanism of Ostwald ripening via liquid-assisted grain growth, where component elements move very quickly through the liquid phase 20 21 . However, in the PJ sample, the Cu 9 Ga 4 alloy did not remain in the absorber layer because of complete selenization at high temperatures; thus, there was no liquid phase.…”

“…The AES data clearly show a much higher peak for sulfur at the surface in the PJ sample than in the PK sample. In the PK sample, Ga appeared on the surface because it diffused outward to the surface via the liquid phase of Cu 9 Ga 4 under partial selenization at low temperatures, leading to the presence of large grains 20 21 .…”

Fabrication of a smooth, large-grained Cu(In,Ga)Se2 thin film using a Cu/(In,Ga)2Se3 stacked precursor at low temperature for CIGS solar cells

“…The growth mechanism is Ostwald ripening with liquid-assisted grain growth where component elements move very fast through the liquid phase. 24,28 At 500 C, the shape of the grain changed to a bamboo shape where the surface area grain was minimized.…”