Analysis of Optical Losses in a Photoelectrochemical Cell: A Tool for Precise Absorptance Estimation

Abstract

Optical losses in a photoelectrochemical (PEC) cell account for a substantial part of solar-to-hydrogen conversion losses, but limited attention is paid to the detailed investigation of optical losses in PEC cells. In this work, an optical model of combined coherent and incoherent light propagation in all layers of the PEC cell based on spectroscopic measurements is presented. Specifically, photoelectrodes using transparent conductive substrates such as F:SnO 2 coated with thin absorber films are focused. The optical model is verified for hematite photoanodes fabricated by atomic layer deposition and successfully used to determine wavelength-dependent reflection, transmission, layer absorptances, and charge generation rates. Furthermore, the calculated absorptances enable 20-30% more accurate calculations of the absorbed photon-to-current efficiency of PEC cells. Our optical model is a powerful tool for the optimization of the optical performance of PEC cells focusing on single absorber or tandem configurations and represents a cornerstone of a complete (optical and electrical) model for PEC water splitting cells.

Coordinated Optical Matching of a Texture Interface Made from Demixing Blended Polymers for High-Performance Inverted Perovskite Solar Cells

“…Thus, to keep the PTAA in the planar inverted structure to fully utilize its advantages, a way must be found to solve this internal optical reflection from the PTAA/perovskite interface. Texture is a widely used method to reduce reflection in the photovoltaic community besides an antireflection coating, which is not applicable for reducing this internal optical reflection because the antireflection coating layer is normally an insulator. Theoretical calculations show that optical engineering including texture can increase light utilization by 20–23% …”

A bright outlook on organic photoelectrochemical cells for water splitting

“…32 Transmission losses should therefore be considered when optimising OPEC photoelectrodes, as they can account for large losses in photocurrent. 33 This work also highlights that light harvesting and catalytic components can be optimised separately because the photocurrent onset potential for hydrogen evolution is determined by the sum of the onset potential for dark electrolysis (carried out by the electrocatalyst) and the photovoltage of the junction (Fig. 4b).…”

High Refractive Index Dielectric Nanoparticles for Optically‐Enhanced Activity of Water‐Splitting Photoanodes

“…A major drawback of the front illumination configuration is the high reflection losses at the electrolyte/metal oxide interface due to the high refractive index of metal oxide semiconductors compared to water. [45][46][47] In this work, we study the benefit of depositing amorphous titania nanoparticles (TiO 2 ), which have no intrinsic photocatalytic activity, on the surface of two different photoanodes: (i) molybdenum-doped bismuth vanadate photoanodes including a cobalt-phosphate oxygen evolution reaction (OER) surface catalyst (Mo:BiVO 4 /CoÀ Pi) and (ii) hematite photoanodes (α-Fe 2 O 3 ). We show that such a decoration with high refractive index nanoparticles can improve the PEC performances under front illumination.…”