RESUMEN
Renewable energy is crucial for sustainable future, and Cu2ZnSnS4 (CZTS) based solar cells shine as a beacon of hope. CZTS, composed of abundant, low-cost, and non-toxic elements, shares similarities with Cu(In,Ga)Se2 (CIGS). However, despite its promise and appealing properties for solar cells, CZTS-based solar cells faces performance challenges owing to inherent issues with CZTS material, and conventional substrate structure complexities. This review critically examines these roadblocks, explores ongoing efforts and breakthroughs, providing insight into the evolving landscape of CZTS-based solar cells research. Furthermore, as an optimistic turn in the field, the review first highlights the crucial need to transition to a superstrate structure for CZTS-based single junction devices, and summarizes the substantial progress made in this direction. Subsequently, dive into the discussion about the fascinating realm of CZTS-based tandem devices, providing an overview of the existing literature as well as outlining the possible potential strategies for enhancing the efficiency of such devices. Finally, the review provides a useful outlook that outlines the priorities for future research and suggesting where efforts should concentrate to shape the future of CZTS-based solar cells.
RESUMEN
Low-cost and washable resistive switching (RS) memory devices with stable retention and low operational voltage are important for higher speed and denser non-volatile memories. In the case of green electronics, pectin has emerged as a suitable alternative to toxic metal oxides for resistive switching applications. Herein, a pectin-based thin film was fabricated on a fluorine-doped tin oxide glass substrate for RS mechanism. The presence of sp3-C groups with low binding energy corresponds to tunable charged defects and the oxygen vacancies confirmed by the O 1s spectra that plays a decisive role in the resistive switching mechanism, as revealed by X-ray photoemission spectroscopy (XPS). The surface morphology of the pectin film shows homogeneous growth and negligible surface roughness (38.98 ± 9.09). The pectin film can dissolve in DI water (10 minutes) owing to its ionization of carboxylic groups, that meet the trends of transient electronics. The developed Ag/pectin/FTO-based memory cell exhibits stable and reproducible bipolar resistive switching behavior along with an excellent ON/OFF ratio (104) and negligible electrical degradation was observed over 30 repeated cycles. Hence, it appears to be a valuable application for green electronics. Indeed, biocompatible storage devices derived from natural pectin are promising for high-density safe applications for information storage systems, flexible electronics, and green electronics.
RESUMEN
A highly cost-effective recycled biomaterial extracted from lime peel has been made biocompatible and has been coated on a commercial fluorine-doped tin oxide (FTO) substrate of glass using the spin coating method. Structural, morphologic, electronic, and antibacterial measurements were thoroughly characterized as a green biomaterial thin film using X-rays (XRD), PL, FTIR, Raman, SEM, HRTEM, AFM, I-V, and antibacterial diffusion techniques. The comprehensive analysis of structures of recyclable waste in the form of lime peel extract (LPE) as thin films showed the crystalline cellulose structure that corresponds to the lattice fringe (0.342 nm) exposed by HRTEM. The K+1 interstitial active sites or vacancies in LPE/FTO thin films are confirmed by the PL spectra that show important evidence about conduction mechanisms, and hence facilitates Ag+1 ion migration from the top to the bottom electrode. The AFM investigations revealed the minor surface roughness (169.61 nm) of the LPE/FTO film, which controls the current leakage that is associated with surface defects. The designed memory cell (Ag/LPE/FTO) exhibits stable, reproducible electrical switching under low operational voltage and is equipped with excellent retention over 5 × 103 s. Furthermore, owing to presence of flavonoids and their superior antioxidant nature, lime peel extract powder shows tremendous antimicrobial activity against gram-positive and Gram-negative bacterial strains.
RESUMEN
Leakage of current in oxide layers is the main issue for higher speed and denser resistive random-access memory. Defect engineering played a substantial role in meeting this challenge by doping or producing controlled interstitial defects or active sites. These controlled active sites enabled memory cells to form a stable and reproducible conduction filament following an electrochemical metallization model. In this study, a defect-abundant lime peel extract (LPE)-mediated anatase TiO2 thin film was fabricated using a simple hydrothermal route. The detailed structural and morphological analysis of the bioactive anatase TiO2-LPE thin film reveals the homogeneous growth of TiO2 flowers and distinct features in terms of controlled defects as compared to simple anatase TiO2. These interstitial defects (Ti+3 and Ti+4) behave as active sites for cation migrations along highly conductive K1+ ions because of the mediation of LPE. The defect-free surface reveals slight surface roughness (4.8 nm) that successfully minimizes leakage of current. The strategy enabled a reliable conductive bridge filament, which can replicate with no more electric degradation. The Ag/TiO2-LPE/FTO-based memory cell demonstrates reproducible bipolar resistive switching along with a high ON/OFF ratio (>105), excellent endurance (1.5 × 103 cycles), and long-term retention (105 s) without any electrical degradation. Furthermore, green-synthesized TiO2-LPE nanoparticles have shown superior antibacterial activity as compared to other green syntheses of different plants or fruits against the toxic microorganisms present in inorganic media.