Browsing by Author "Krajangsang T."

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    Enhanced Performance and Stability of Fully Printed Perovskite Solar Cells and Modules by Ternary Additives under High Humidity
    (2023-04-20) Srisamran N.; Sudchanham J.; Sriprachuabwong C.; Srisawad K.; Pakawatpanurut P.; Lohawet K.; Kumnorkaew P.; Krajangsang T.; Tuantranont A.; Mahidol University
    To scale up from perovskite solar cells (PSCs) to perovskite solar modules (PSMs), a printing technique with an economical, uncomplicated fabrication process is required to meet the industrial market requirements. Equally important are the high photovoltaic (PV) performance and long-term device stability needed for successful commercialization of the technology. In this study, the effect of ternary additives consisting of guanidinium thiocyanate (GT), thiourea (TU), and urea (U) in MAPbI3 films on power conversion efficiency (PCE) as well as device stability was investigated for the first time based on the experimental results. GT helped influence perovskite crystal grain enlargement, while TU facilitated the perovskite crystal growth, leading to an increase in the current density. Moreover, the use of U was found to reduce the loss in open-circuit voltage as well as the hysteresis of PSC devices. An optimal composition of the ternary additives (1:1:2 molar ratio of GT, TU, and U) resulted in the outstanding performance of fully printed PSCs, showing a PCE of 16.40%, which was significantly higher than that of the pristine device (8.01%). In addition, the unencapsulated device prepared using the ternary additives showed great stability over 1000 h with a PCE retention of 100%, while the PCE of the unencapsulated pristine device decreased by 41.79%. For the large-scale PSM, the ternary additives yielded a significant enhancement of 11.60% PCE, which was over 3 times higher than that for the PSM without additives, as well as 100% retention after 2000 h of both desiccator and ambient storage.
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    Intermediate matching layer for light-induced performance and removable clip-on applications of four-terminal perovskite/silicon heterojunction tandem solar cells
    (2023-05-01) Sanglee K.; Sakunkaewkasem S.; Piromjit C.; Nukunudompanich M.; Kanjanaboos P.; Chuangchote S.; Suttiruengwong S.; Sahasithiwat S.; Limmanee A.; Krajangsang T.; Mahidol University
    Perovskite/silicon tandem solar cells are one of the most efficient ways to improve the performance of the photovoltaic industry and should be viewed as a promising path in the photovoltaic field. The silicon photovoltaic modules have a lifespan of over 20 years, while the low device stability of perovskite solar cells (PSCs) remains a significant commercialization barrier. An air gap acts as an optical spacer layer for four terminal (4T) perovskite/silicon tandem cells, resulting in a loss of efficiency. Using polydimethylsiloxane (PDMS) as an intermediate matching layer (IML) and a clip-on design made of a PDMS-based material sandwiched between polyvinyl chloride (PVC) layers with the configuration of PVC/IML/PVC, this research not only achieved efficiency improvement of four-contact tandem solar cells but also greatly simplified disassembly of individual cells. The 4T perovskite/silicon heterojunction tandem cells with a clip-on design achieved the highest efficiency of 23.49% for the active area of 1 cm2, while the fully tandem configuration without a clip-on layer only exhibited a PCE of 22.83%. The clip-on technology has the potential to boost the current density of silicon heterojunction solar cells from 15.01 mA/cm2 (for the filtered bottom cell with an air gap) up to 16.51 mA/cm2 (for the filtered bottom cell with a clip-on). Therefore, this state-of-the-art allows for the removal of PSCs with a shorter lifespan while adhering two photovoltaic cells together securely and effectively.
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    Investigation of Double-Layered Pb-Sn Perovskite Absorbers: Formation, Structure, Band Alignment, and Stability
    (2022-01-27) Naikaew A.; Kumnorkaew P.; Wattanathana W.; Swe K.Z.; Pansa-Ngat P.; Amratisha K.; Nakajima H.; Supruangnet R.; Krajangsang T.; Sinthiptharakoon K.; Sahasithiwat S.; Kanjanaboos P.; Mahidol University
    Mixed Pb/Sn halide perovskites have shown wide band gap tunability, allowing these materials to become practical components. Nevertheless, a high density of Sn vacancies and an undesirable oxidation of Sn(II) to Sn(IV), even in the absence of any oxidant species, diminish film performance and air-stability due to recombination losses of charge carriers. More recently, A-site substitution by several organic halide compounds as additives has been engaged to improve film stability through dangling bond passivation. However, exploring the roles of passivation via A-site doping in Pb/Sn perovskites requires a more insightful investigation. Here, we explicate the structural design of 2D perovskite formation on the 2D/3D mixed Pb/Sn perovskite layer and its effects on electronic properties and stability. Surprisingly, we observe that PEAI treatment causes 2D perovskite formation at the interface of the layered perovskite. In situ growth of the 2D perovskite significantly suppresses Sn and I vacancies via Lewis base passivation. With the control of the conversion process, the interfacial 2D establishes on top of the layered perovskite, resulting in valence-band maximum down-shifting, which in turn adjusts the energy level. Remarkably, the crystallinity along with the more preferred (100) orientation is significantly improved by the PEAI treatment. The phase stability under ambient conditions is enhanced as a result of the 2D passivation. Through various characterization methods, the deep investigation of 2D perovskite interfacial formation was carefully engaged, yielding insights highly beneficial for various optoelectronic applications.
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    Photoexcitation of perovskite precursor solution to induce high-valent iodoplumbate species for wide bandgap perovskite solar cells with enhanced photocurrent
    (2023-12-01) Naikaew A.; Krajangsang T.; Srathongsian L.; Seriwattanachai C.; Sakata P.; Burimart S.; Sanglee K.; Khotmungkhun K.; Ruankham P.; Romphosri S.; Limmanee A.; Kanjanaboos P.; Mahidol University
    Solution-processed organic–inorganic hybrid perovskite solar cells are among the candidates to replace the traditional silicon solar cells due to their excellent power conversion efficiency (PCE). Despite this considerable progress, understanding the properties of the perovskite precursor solution is critical for perovskite solar cells (PSCs) to achieve high performance and reproducibility. However, the exploration of perovskite precursor chemistry and its effects on photovoltaic performances has been limited thus far. Herein, we modified the equilibrium of chemical species inside the precursor solution using different photoenergy and heat pathways to identify the corresponding perovskite film formation. The illuminated perovskite precursors exhibited a higher density of high-valent iodoplumbate species, resulting in the fabricated perovskite films with reduced defect density and uniform distribution. Conclusively, the perovskite solar cells prepared by the photoaged precursor solution had not only improved PCE but also enhanced current density, confirmed by device performance, conductive atomic force microscopy (C-AFM), and external quantum efficiency (EQE). This innovative precursor photoexcitation is a simple and effective physical process for boosting perovskite morphology and current density.