Low-temperature mesoporous chalcogenide photoelectrodes
© 2015 EPFL
Templating nanocrystals into mesoporous electrodes using an organic porogen typically requires thermal oxidation at >400 °C to completely remove the organic material and afford good electronic properties. Dr. Guijarro of LIMNO demonstrates in a new paper that low temperature electrodes can be prepared using a novel, autodecomposition porogen.
The work demonstrates that nitrocellulose can afford mesoporous CdS and CZTS nanocrystal thin film electrodes at only 250–300 °C in air or under argon. Remarkable control over the surface area and the average pore size (20–100 nm) in thin films are demonstrated by varying the ratio of preformed nanocrystals and nitrocellulose. Moreover the mesoporous electrodes exhibit excellent optoelectronic properties. Photoelectrochemical performance is enhanced due to the increased active surface area, showing an 8-fold photocurrent increase over compact nanocrystal films, and an IPCE over 70%.