Abstracts Book - IMRC 2018

• SC4-P049
STABLE CUBIC TIN SULFIDE THIN FILMS OBTAINED BY CHEMICAL
SOLUTION DEPOSITION
Juniet Rebeca Gaitan Arevalo 1 , Luis GONZALEZ 1 , Jose Escorcia Garcia 2
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV Unidad Saltillo,
Ingeniería Cerámica, Mexico. 2 CONACYT, Cinvestav Unidad Saltillo., Ingeniería Cerámica,
Mexico.
Tin sulfide (SnS) thin films have been widely employed as solar cell absorbing
material due to its high absorption coefficient, narrow band gap, a high mobility
of the photo-generated carriers, among other properties. However, those
characteristics have been obtained with the most common and stable form of
SnS, orthorhombic structure. This work contains the preparation of SnS thin
films with simple cubic structure, a newly discovered phase, which is obtained
by chemical bath using nitrilotriacetic acid as complexing agent. The effect of the
pH in the solution and the annealing temperature on the structural, optical and
electrical properties of the deposited films was studied. An increase in the pH
from 9.22 to 9.72 promoted a better crystallinity of the films resulting in an
increase of the crystallite size from 8.5 to 36.9 nm, respectively. In addition, the
grain size of the films also increases with the pH from 80 nm to 176 nm. On the
other hand, the band gap of the deposited films decreased with the pH from
1.89 to 1.79 eV. Also, the pH caused an increase in the conductivity of the
deposited films, which was of the order of 10 -7 Ω -1 cm -1 . The hot-probe test
showed a p-type conductivity in the SnS films. Finally, after the thermal
treatments carried out at temperatures of 200 and 300 ° C, it was possible to
retain the SnS phase stable with simple cubic structure, which is of great
relevance in the development of thin film solar cells by chemical solution
deposition, since usually it is necessary a post-annealing treatment of the cells
to crystallize and improve their optical and electrical properties without losing
their crystalline structure as happened in other SnS materials.
Keywords: simple cubic, tin sulfide thin films, nitrilotriacetic acid
Presenting authors email: juniet.gaitan@cinvestav.edu.mx