Researchers from Malaysia have advanced the development of next-generation bifacial dye-sensitized solar cells (DSSCs) by integrating graphene into a trilayer photoanode configuration to boost both efficiency and stability. The team focused on a titanium dioxide (TiO₂)–based [T/sp-P25-T/sp] stack formation framework, where varying concentrations of graphene (0.05%, 0.1%, and 0.2%) were introduced to optimize electron transport and suppress recombination losses.
Among the tested samples, the photoanode doped with 0.1% graphene achieved the best performance, delivering a combined power conversion efficiency (PCE) of 11.09% under dual illumination and maintaining 10.31% after ten days of operation. This represents an improvement over undoped TiO₂ structures. Key analytical techniques - including FESEM, EDS, Raman spectroscopy, XRD, UV–Vis spectroscopy, and electrochemical impedance spectroscopy (EIS) - confirmed that graphene was successfully embedded within the anatase TiO₂ matrix without structural compromise.
Importantly, EIS results revealed that graphene incorporation reduced charge transfer resistance and extended electron lifetime to over 63 seconds, while the short-circuit current density increased to 17.04 mA cm⁻² from 15.99 mA cm⁻² in standard configurations. These outcomes are attributed to graphene’s high electrical conductivity and its ability to facilitate faster electron mobility across the trilayer junction.
This work is among the first to demonstrate a graphene-enhanced trilayer TPT photoanode for bifacial DSSCs, surpassing 11% combined efficiency with durable long-term stability under front and back illumination. The findings not only validate graphene’s role as an effective dopant for TiO₂ but also underscore its potential in advancing building-integrated photovoltaics (BIPVs). Future research will aim to refine the doping process, assess scalability, and evaluate outdoor performance over extended durations.
By leveraging the unique properties of graphene, the Malaysian researchers highlight a practical route toward more efficient, transparent, and stable solar energy systems, bridging laboratory innovation with architectural integration.
