A framework for understanding efficient diurnal CO2 reduction using Si and GaAs photocathodes

An Expansion of Polarization Control Using Semiconductor–Liquid Junctions

“…Attempting direct bias application at the liquid junction of a buried junction device does not enable light-dependent modulation of current in any respect, as the bulk metal characteristics of buried-junction PEC devices make their metallized interfaces insensitive to photoillumination, unless a back-contact is used (section S.9). However, in the case of the PEC device presented here, bias application between the anode front contact and cathode (configuration i) does preserve light responsiveness, which is a consequence of a semiconductor–liquid junction displaying genuine Schottky diode behavior.…”

“…Biasing this cell between the photoanode’s Ti back contact and cathode (configuration ii) displays the light-dependent polarization typical of a photoelectrolyzer, with a negative shift (60–200 mV) in bias response observed as a result of the photovoltage generated across the semiconducting anode. − However, independent voltage sensing of the cell potential between the Au front anode contact and the device cathode is found to be unstable as a function of changing the light intensity (and current). , By contrast, voltage application between the photoanode’s Au surface contact and the dark cathode results in a current response with significantly reduced shifts in junction potential as a function of light intensity. In configuration i, measurement of the applied cell potential is found to remain relatively stable as current is arbitrarily switched by changing the intensity of photoanodic insolation.…”

Modeling diurnal and annual ethylene generation from solar-driven electrochemical CO2 reduction devices

“…Recent work has begun to address this challenge, focusing on solar-driven hydrogen evolution [23][24][25][26][27] and solar-driven CO 2 R under conditions of variable irradiation. [28][29][30][31][32][33] However, there remains a need to develop tools 34 that aid in the understanding and prediction of transient, diurnal performance of integrated solar-fuels devices for complex, multi-product electrochemical reactions and the consequences of environmental conditions on the large-scale feasibility of these devices.…”

Utilizing three-terminal, interdigitated back contact Si solar cells as a platform to study the durability of photoelectrodes for solar fuel production

“…However, under real outdoor operating conditions, a semiconductor photoabsorber operating as a photoelectrode needs to be stable under day/night (diurnal) lighting conditions. 8,28–32 Small band gap semiconductors ( e.g. Si) utilize more of the solar spectrum than large band gap semiconductors ( e.g.…”