Eur. Phys. J. Appl. Phys. 100, 25 (2025)
https://doi.org/10.1051/epjap/2025024

Original Article

SCAPS-1D simulation of lead-free Cs₂TiBr₆ based perovskite solar cells: the impact of electron and hole transport layers

¹ Materials Laboratory, Department of Chemistry, Mirpur University of Science and Technology (MUST), Mirpur - 10250(AJK), Pakistan
² Henan Key Laboratory of Photovoltaic Materials, School of Physics and Electronics, Henan University, Kaifeng, 475004 Henan, P.R. China
³ School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou, 450001 Henan, P.R. China
⁴ Department of Chemistry, Allama Iqbal Open University, Islamabad 44000, Pakistan
⁵ School of Computing Sciences, Pak-Austria Fachhochschule Institute of Applied Sciences (PAF-IAST), Mang, Haripur, Pakistan
⁶ Centre for Smart Systems and Automation, COE for Robotics and Sensing Technologies, Multimedia University, 63100 Cyberjaya, Selangor, Malaysia
⁷ Faculty of Artificial Intelligence and Engineering, Multimedia University, 63100 Cyberjaya, Malaysia
⁸ Department of Chemical Engineering, Faculty of Engineering, Islamic University of Madinah, Madinah, Abo Bakr Al Siddiq, Al Jamiah, Madinah 42351, Saudi Arabia
⁹ The Department of Chemistry, Faculty of Science, The Islamic University of Madinah, Madinah, Abo Bakr Al Siddiq, Al Jamiah, Madinah 42351, Saudi Arabia
¹⁰ Nanomaterials Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
¹¹ Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, ON K7L 3N6, Canada

^* e-mail: amir.chem@must.edu.pk.
^** e-mail: hha@iu.edu.sa.
^*** e-mail: nunzijm@queensu.ca.
^**** e-mail: Shahiduzzaman@se.kanazawa-u.ac.jp.

Received: 5 March 2025
Accepted: 22 August 2025
Published online: 17 September 2025

Abstract

Perovskite solar cells (PSCs) have garnered significant attention due to their remarkable power conversion efficiency, yet concerns surrounding the stability and toxicity of lead halide perovskites have hindered their full-scale commercialization. In addressing this dilemma which arise in part from energy band misalignment, this study employs computational modeling to investigate Cs₂TiBr₆ PSCs connected through various hole transport layers (HTLs) and electron transport layers (ETLs). Furthermore, a comprehensive investigation of parameters such as the absorber layer thickness, defect density, operating temperature, and rear metal electrode configuration has been conducted to optimize the photovoltaic performance. Through systematic optimization, a promising configuration comprising the layer sequence Glass/FTO/ZnO/Cs₂TiBr₆/CZTSe/Au has been identified, yielding a potential power conversion efficiency of 20.40%. Additionally, an alternative configuration, Glass/FTO/ZnO/Cs₂TiBr₆/CZTSe/Pt, has suggested a further enhancement in power conversion efficiency up to 30.37%. Notably, this configuration yields the highest V_oc of 1.21 V, Jsc of 28.24 mA/cm², and FF of 89.12%, resulting in an impressive PCE of 30.61% when selenium (Se) is used instead of Platinum (Pt) as the back contact material. The exceptional performance of the CZTSe HTL is attributed to the quantum efficiency (QE) of the device, which indicates a proper alignment of its energy bands with those of the double perovskite absorber layer. This synergetic alignment is deemed responsible for improved efficiency.