Combined Raman‐DLTS investigations of n‐type Cu–In–S absorber layers grown on Cu tape substrate (CISCuT)

Abstract

Thin absorber films grown by the CuInS 2 -on-Cu-tape (CISCuT) method were studied by Raman spectroscopy and deep-level transient spectroscopy (DLTS). Raman measurements revealed a degradation of crystalline quality and a growth of the CuAu fraction with the increase of Cu-tape velocity through the sulfur chamber, whereas DLTS method -corresponding variations in the magnitude of the dominating peak E1. The origin of the E1 peak was established from the correlation of Raman and DLTS results and ascribed to defect states at the interface between chalcopyrite and CuAu phase.

Nanophase CuInS2 nanosheets/CuS composite grown by the SILAR method leads to high performance as a counter electrode in dye sensitized solar cells

“…15 The 322 cm À1 (B 2 1 TO) and 351 cm À1 (B 2 1 LO) are also from CH ordering. 19 the images for the sample annealed at 500 C. These establish that the lms comprise of uniform and compact nanosheets which are vertically oriented and interconnected, forming multiple semiconducting channels. In DSSCs, the catalytic reactions take place on the surface of the counter electrodes, thus it is credible that the morphologies of catalytic materials will have an obvious inuence on the catalytic reactions.…”

“…13 Briey, the above mentioned substrates were dipped sequentially in aqueous solutions of 0.1 M In 2 (Cl) 3 for 60 s, and S ion precursor solution (0.075 M Na 2 S, with a pH equal to 11.3 adjusted by a buffer solution of 0.1 M KH 2 PO 4 and 0.1 M NaOH) for 150 s. This was followed by dipping in 0.01 M CuCl 2 aqueous solution for 20 s, and again in S ion precursor solution for 150 s. Between each dip, the lms were rinsed with de-ionized water for 30 s to remove excess precursors and dried in air before the next dipping. Such an immersion procedure is termed as one cycle for copper indium sulde deposition, and this immersion cycle was repeated several times (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) until the desired amount of Cu x In y S z quantum dots (QDs) were incorporated. To increase the crystallinity of SILAR-deposited CuInS 2 , samples were annealed at different temperatures (250 C and 500 C) in a split-tube furnace under sulfur atmosphere/Ar gas for 30 min at a ramp of 2 C min À1 .…”