Role of chelate complexes in densification of CuInSe2 (CIS) thin film prepared from amorphous Cu–In–Se nanoparticle precursors

Abstract

CuInSe 2 (CIS) absorber layers for thin film solar cells were fabricated via a non-vacuum route using amorphous Cu-In-Se nanoparticle precursors prepared by a low temperature colloidal process within one minute of reaction without any external heating. In particular, we intentionally added a chelating agent to the nanoparticle colloid in order to increase the density of the final films by enhancing the viscous flow of precursor materials during high temperature selenization. This is based on the decreased reactivity of precursor particles due to the formation of chelate complexes at particle surfaces. While the CIS films formed from the amorphous Cu-In-Se particles without surface modification were found to have large voids, those formed from surface modified particles showed flat and dense morphologies. In accordance with the improvements in the film morphology and density, efficiencies of the devices were also significantly increased from 0% (complete short circuit in the case without surface modification) to 4.41% (with surface modification).

Towards low-cost, environmentally friendly printed chalcopyrite and kesterite solar cells

“…Nevertheless, due to the high melting temperature of crystalline particles, they might not be necessarily the best choice for device fabrication. Ahn et al 121,122 reported the synthesis and utilization of amorphous Cu-In-Se nanoparticles, aiming to benet from the lower melting temperatures of such particles to assist an effective sintering during a post-thermal treatment. CuInSe 2 lms formed from amorphous Cu-In-Se nanoparticles showed dense morphologies for particles modied by chelate complexation with ethanolamine.…”

A chelating effect in hybrid inks for non-vacuum-processed CuInSe2 thin films

“…The chelating effect of MEA in the hybrid ink is easily observed by the visible color change of the solution in hybrid inks. 3,15,16 A clear solution was obtained for the hybrid ink lacking MEA, but the solution turned blue when MEA was included. From the ICP elemental analysis, 1.88% of Cu was detected in the hybrid ink solution with MEA following the precipitation of Cu-Se nanoparticles; however, no Cu was detected in the hybrid ink without MEA following Cu-Se nanoparticle precipitation.…”

Solution processed CdTe/CdSe nanocrystal solar cells with more than 5.5% efficiency by using an inverted device structure

“…[1][2][3] To date, III-V NCs including PbS, 4 PbSe 5 and PbS x Se 1Àx (ref. On the other hand, solar cells based on sintering NCs such as CuInS 2 , 7 CuInSe 2 8 and CdTe [9][10][11][12][13][14][15] have also been investigated and good device performances have been obtained. On the other hand, solar cells based on sintering NCs such as CuInS 2 , 7 CuInSe 2 8 and CdTe [9][10][11][12][13][14][15] have also been investigated and good device performances have been obtained.…”