Phosphotungstic Acid Regulated Chemical Bath Deposition of Sb₂S₃ for High‐Efficiency Planar Heterojunction Solar Cell

Abstract

Chemical bath deposition is a convenient method for preparing Sb2S3 film which is considered as a promising photovoltaic material. However, impurity phases such as Sb2O3, SbOCl, Sb2(SO4)3 and Sb(OH)3 are inevitably generated in this solution process. Herein, we demonstrate that phosphotungstic acid in the precursor solution is able to suppress the formation of oxide and oxyhalide by‐products, leading to considerably optimized composition and crystallinity for solar cell applications. With this method, a remarkable improvement of power conversion efficiency from 1.91 % to 4.61 % is obtained, which is also the highest efficiency in planar heterojunction solar cells by solution processed Sb2S3 absorber layer.

Boosting VOC of antimony chalcogenide solar cells: A review on interfaces and defects

“…Similarly, Zhang et al found that phosphotungstic acid (PW) additive was an efficient method to suppress the formation of oxide impurities (such as Sb 2 O 3 and Sb 2 (SO 4 ) 3 ) in the Sb 2 S 3 film growth process, leading to considerably optimized surface impurities defects and film crystallinity for Sb 2 S 3 solar cells. [160] The surface of Sb 2 Se 3 films may be covered by certain amount of Sb 2 O 3 or elemental Se, which will act as the charge traps, resulting in a high back contact resistance and thereby low FF (50%). Sb 2 O 3 and elemental Se can be removed from the Sb 2 Se 3 back surface by (NH 4 ) 2 S etching.…”

“…found that phosphotungstic acid (PW) additive was an efficient method to suppress the formation of oxide impurities (such as Sb 2 O 3 and Sb 2 (SO 4 ) 3 ) in the Sb 2 S 3 film growth process, leading to considerably optimized surface impurities defects and film crystallinity for Sb 2 S 3 solar cells. [ 160 ]…”

Sb2S3 solar cells with a cost-effective and dopant-free fluorene-based enamine as a hole transport material

“…The electron transport layer (ETL) and hole transport material (HTMs) ferry the electrons and holes generated in the absorber to the contacts, respectively. 3,5,[22][23][24][25][26] Indium tin oxide (ITO) and uorine doped tin oxide (FTO) are commonly used TCOs. 22,23,27 For HTMs, several organic and inorganic materials are explored.…”

“…27,29 More importantly, they need to be transparent in the visible spectral region when used in semitransparent solar cells and should be cost-effective. The most popular HTMs explored to date for Sb 2 S 3 solar cells are the organic-based P3HT (poly(3-hexylthiophene)), 3,5,22,27 spiro-OMeTAD (2,2 0 ,7,7 0 -tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9 0 -spirobi-uorene), 24,25 PEDOT:PSS (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) 23 and PCPDTBT (poly [2,6-(4,4- 30 Among inorganic materials, NiO x , 31 V 2 O 5 32 and CuSCN:KSCN 6 have been reported as HTMs. For instance, Kim et al have fabricated planar Sb 2 S 3 solar cells with spin coated PEDOT:PSS as the HTM wherein Sb 2 S 3 is deposited using CBD, and have obtained a PCE of 5.8%.…”

“…Zhang et al have used CBD to deposit Sb 2 S 3 with spiro-OMeTAD as the HTM and have reported an efficiency of 5.5%. 24 Chen et al have adopted spin coating for Sb 2 S 3 deposition with spiro-OMeTAD as the HTM and demonstrated a PCE of 5.2%. 25 Choi et al have deposited Sb 2 S 3 using CBD and have employed a combination of PCPDTBT and PEDOT:PSS as the HTM and fabricated solar cells (FTO/mp-TiO 2 /Sb 2 S 3 /PCPDTBT/PEDOT:PSS/Au) with a PCE of 7.5%, which remains the highest to date.…”