TY  - EJOU
AU  - Houaidji, Naoual 
AU  - Kamli, Kenza 
AU  - Hadef, Zakaria 
AU  - Chouial, Houssem Eddine 
AU  - Bendaia, Marwa 

TI  - FeS<sub>2</sub> Film Properties and FeS<sub>2</sub>/Co-doped SnS<sub>2</sub> Heterojunction for Photovoltaics Applications
T2  - Chalcogenide Letters

PY  - 2026
VL  - 23
IS  - 3
SN  - 1584-8663

AB  - We present a systematic investigation of FeS<sub>2</sub> thin films deposited by ultrasonic spray pyrolysis (USP) at different deposition times (15–40 min), with the aim of understanding their structural, optical, and electrical evolution and their suitability for heterojunction device applications. Particular attention is given to the integration of the optimized FeS<sub>2</sub> layer with a Co-doped SnS<sub>2</sub> bottom layer to form a p–n heterojunction. Structural analysis by X-ray diffraction reveals a transition from an amorphous/oxidized phase at short deposition times toward well-crystallized pyrite after 25 min, while the 40-min film exhibits the most intense reflections and the largest crystallite size. Optical investigations indicate a progressive increase in film thickness from 0.23 to 1.53 μm between 20 and 40 min, accompanied by a reduction in the apparent optical band gap from 2.34 eV to 1.60 eV, consistent with improved crystallinity and enhanced light absorption. Electrical measurements further show a decrease in resistivity with increasing deposition time, together with improved carrier mobility and higher carrier concentration, confirming the enhancement of transport properties. The optimized FeS<sub>2</sub> layer was subsequently coupled with a SnS<sub>2</sub>:Co film to fabricate a heterostructure, and current–voltage measurements reveal a pronounced rectifying response, confirming junction formation and charge separation at the interface. These findings demonstrate that deposition time plays a key role in tailoring FeS<sub>2</sub> film properties and that the FeS<sub>2</sub>/SnS<sub>2</sub>:Co architecture constitutes a promising, low-cost heterojunction platform for future optoelectronic and photovoltaic device applications.
KW  - FeS<sub>2</sub> films; ultrasonic spray; X-ray diffraction; optical properties; deposition times effect; FeS<sub>2</sub>/SnS<sub>2</sub>:Co heterojunction; solar cell

DO  - 10.32604/cl.2026.076383