Zn(O,S) Buffer Layer for in Situ Hydrothermal Sb₂S₃ Planar Solar Cells

Abstract

Hydrothermal deposition is emerging as a highly potential route for antimony-based solar cells, in which the Sb2(S,Se)3 is typically in situ grown on a common toxic CdS buffer layer. The narrow band gap of CdS causes a considerable absorption in the short-wavelength region and then lowers the current density of the device. Herein, TiO2 is first evaluated as an alternative Cd-free buffer layer for hydrothermally derived Sb2S3 solar cells. But it suffers from a severely inhomogeneous Sb2S3 coverage, which is effectively eliminated by inserting a Zn­(O,S) layer. The surface atom of sulfur in Zn­(O,S) uniquely provides a chemical bridge to enable the quasi-epitaxial deposition of Sb2S3 thin film, confirming by both morphology and binding energy analysis using DFT. Then the results of the first-principles calculations also show that Zn­(O,S)/Sb2S3 has a more stable structure than TiO2/Sb2S3. The resultant perfect Zn­(O,S)/Sb2S3 junction, with a suitable band alignment and excellent interface contact, delivers a remarkably enhanced J SC and V OC for Sb2S3 solar cells. The device efficiency with the TiO2/Zn­(O,S) buffer layer boosts from 0.54% to 3.70% compared with the counterpart of TiO2, which has a champion efficiency of Cd-free Sb2S3 solar cells with a structure of ITO/TiO2/Zn­(O,S)/Sb2S3/Carbon/Ag by in situ hydrothermal deposition. This work provides a guideline for the hydrothermal deposition of antimony-based films upon a nontoxic buffer layer.

A Robust Hydrothermal Sulfuration Strategy toward Effective Defect Passivation Enabling 6.92% Efficiency Sb2S3 Solar Cells

“…It can be obviously seen that the (020), (120), ( 220), ( 130), (310), ( 021), ( 230), (211), and (221) diffraction peaks are existed in the five types of Sb 2 S 3 samples, which suggests the formation of high-crystallinity Sb 2 S 3 films. [36][37][38] Surprisingly, the diffraction intensities order of (120) and (211) peaks in Sb 2 S 3 -control, Sb 2 S 3 -0.1, Sb 2 S 3 -0.2, Sb 2 S 3 -0.3, and Sb 2 S 3 -0.4 films are Sb 2 S 3 -0.4 > Sb 2 S 3 -0.3 % Sb 2 S 3 -0.2 % Sb 2 S 3 -0.1 > Sb 2 S 3 -control (Figure 3b). This reveals that hydrothermal sulfuration could enhance the crystallinity at a mild heating temperature (160 °C), and the sulfuration effect is related to the volume of the (NH 4 ) 2 S. Furthermore, the SEM results demonstrate that the grain size of Sb 2 S 3 film did not change after hydrothermal sulfuration (Figure 2a-e).…”

Post-Treatment of TiO2 Film Enables High-Quality Sb2Se3 Film Deposition for Solar Cell Applications

“…Considering this, intensive efforts have been made to exploit novel metal chalcogenides materials. To date, the emerging Cu 2 ZnSn­(S,Se) 4 , AgBiS 2 , AgSbS 2 , SnS, GeSe, CdSe, Sb 2 (S,Se) 3 , − Sb 2 S 3 , − Sb 2 Se 3 , , and so on, have been applied in solar cell fabrication. Among them, the quasi-one-dimensional semiconductor, Sb 2 Se 3 , which possesses a suitable bandgap (1.1–1.3 eV), high absorption coefficient, excellent optical and electrical properties, abundant elemental reserves, remarkable stability to air and moisture, and environmentally friendly characteristics, is regarded as a promising light absorption material.…”

Molten Salts Assisted Interfacial Engineering for Efficient and Low‐Cost Full‐Inorganic Antimony Sulfide Solar Cells

“…[19] In order to further reduce the manufacturing cost of the device, Chen et al applied cheaper carbon instead of Au as electrode in Sb 2 S 3 plane solar cells, achieving a moderate efficiency of 3.7%. [20] On the other hand, inorganic HTMs such as V 2 O 5 , NiO x , and Sb 2 Se 3 are also introduced between the absorption layer and the rear electrode, which inhibits the recombination of carriers at the back interface and accelerates the transport of carriers to a certain extent. [21,22] Among them, the highest PCE of 5.8% for a fullinorganic Sb 2 S 3 solar cell with Sb 2 Se 3 as HTM was reported.…”