66 research outputs found
Efficient photosynthesis of carbon monoxide from CO2 using perovskite photovoltaics
Artificial photosynthesis, mimicking nature in its efforts to store solar energy, has received considerable attention from the research community. Most of these attempts target the production of H2 as a fuel and our group recently demonstrated solar-to-hydrogen conversion at 12.3% efficiency. Here, in an effort to take this approach closer to real photosynthesis, which is based on the conversion of CO2, we demonstrate the efficient reduction of CO2 to carbon monoxide driven solely by simulated sunlight using water as the electron source. Employing series-connected perovskite photovoltaics and high-performance catalyst electrodes, we reach a solar-to-CO efficiency exceeding 6.5%, which represents a new benchmark in sunlight-driven CO2 conversion. Considering hydrogen as a secondary product, an efficiency exceeding 7% is observed. Furthermore, this study represents one of the first demonstrations of extended, stable operation of perovskite photovoltaics, whose large open-circuit voltage is shown to be particularly suited for this process
Recommended from our members
New Strategies for Defect Passivation in High-Efficiency Perovskite Solar Cells
Lead halide perovskite solar cells now show excellent efficiencies and encouraging levels of stability. Further improvements in performance require better control of the trap states which are considered to be associated with vacancies and defects at crystallite surfaces. Herein, a reflection on the ways in which these traps can be mitigated is presented by improving the quality of the perovskite layer and interfaces in fully assembled device configurations. In this review, the most recent design strategies reported in the literature, which have been explored to tune grain orientation, to passivate defects, and to improve charge-carrier lifetimes, are presented. Specifically, the advances made with single-cation, mixed-cation and/or mixed-halide, and 3D/2D bilayer-based light absorbers are discussed. The interfacial, compositional, and band alignment engineering along with their consequent effects on the open-circuit voltage, power conversion efficiency, and stability are a particular focus
Highly efficient planar perovskite solar cells through band alignment engineering
The simplification of perovskite solar cells (PSCs), by replacing the mesoporous electron selective layer (ESL) with a planar one, is advantageous for large-scale manufacturing. PSCs with a planar TiO2 ESL have been demonstrated, but these exhibit unstabilized power conversion efficiencies (PCEs). Herein we show that planar PSCs using TiO2 are inherently limited due to conduction band misalignment and demonstrate, with a variety of characterization techniques, for the first time that SnO2 achieves a barrier-free energetic configuration, obtaining almost hysteresis-free PCEs of over 18% with record high voltages of up to 1.19 V
Influence of the Nature of A Cation on Dynamics of Charge Transfer Processes in Perovskite Solar Cells
A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells
Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many
years because of their potential for large-scale manufacturing using roll-to-roll processing
allied to their use of earth abundant raw materials. Two main challenges exist for DSC
devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently
achieved for laboratory-scale âheroâ cells and replacement of the widely-used liquid
electrolytes which can limit device lifetimes. To increase device efficiency requires optimized
dye injection and regeneration, most likely from multiple dyes while replacement
of liquid electrolytes requires solid charge transporters (most likely hole transport materials
â HTMs). While theoretical and experimental work have both been widely applied to
different aspects of DSC research, these approaches are most effective when working in
tandem. In this context, this perspective paper considers the key parameters which
influence electron transfer processes in DSC devices using one or more dye molecules
and how modelling and experimental approaches can work together to optimize electron
injection and dye regeneration.
This paper provides a perspective that theory and experiment are best used in tandem to study
DSC device
One-step mechanochemical incorporation of an insoluble cesium additive for high performance planar heterojunction solar cells
Self-assembled photosystem-I biophotovoltaics on nanostructured TiO2 and ZnO
The abundant pigment-protein membrane complex photosystem-I (PS-I) is at the heart of the Earthâs energy cycle. It is the central molecule in the âZ-schemeâ of photosynthesis, converting sunlight into the chemical energy of life. Commandeering this intricately organized photosynthetic nanocircuitry and re-wiring it to produce electricity carries the promise of inexpensive and environmentally friendly solar power. We here report that dry PS-I stabilized by surfactant peptides functioned as both the light-harvester and charge separator in solar cells self-assembled on nanostructured semiconductors. Contrary to previous attempts at biophotovoltaics requiring elaborate surface chemistries, thin film deposition, and illumination concentrated into narrow wavelength ranges the devices described here are straightforward and inexpensive to fabricate and perform well under standard sunlight yielding open circuit photovoltage of 0.5â
V, fill factor of 71%, electrical power density of 81â
”W/cm2 and photocurrent density of 362â
”A/cm2, over four orders of magnitude higher than any photosystem-based biophotovoltaic to date
Boosting the Efficiency of Perovskite Solar Cells with CsBr-Modified Mesoporous TiO2 Beads as Electron-Selective Contact
- âŠ