Copper Chalcopyrite Film Photocathodes for Direct Solar-Powered Water Splitting

ABSTRACTIn search of an efficient semiconductor material for direct photoelectrochemical (PEC) hydrogen production, chalcopyrite films in the Cu(In,Ga)Se2 system (CIGS) with bandgaps of 1.3-1.65 eV have been evaluated. The films have been fabricated by 2-stage and 3-stage co-evaporation processes. Film samples have been fabricated into CIGS/CdS solar cells for evaluation of solid-state device properties, and into CIGS photocathodes for evaluation of the photoelectrochemical hydrogen-production characteristics. The PEC current-potential scans of the photocathodes in 0.5M sulfuric acid show photocurrents of 18-27 mA/cm2 under simulated AM1.5 global light (100 mA/cm2) at sufficient cathodic potential bias. In terms of fill factor of the photocurrent curves, electrodes with molybdenum back contact are superior to SnO2:F back contact because of better conductivity. The morphology as seen in scanning electron micrographs is unchanged after initial PEC testing in the cathodic regime, suggesting films are stable.

Download Full-text

(Invited) Development of Wide Bandgap Copper Chalcopyrite Materials for Economical Photoelectrochemical Hydrogen Production

ECS Meeting Abstracts ◽

10.1149/ma2016-02/49/3630 ◽

2016 ◽

Keyword(s):

Hydrogen Production ◽

Wide Bandgap ◽

Copper Chalcopyrite ◽

Photoelectrochemical Hydrogen Production

Download Full-text

Wide Bandgap Copper Chalcopyrite Materials for Photoelectrochemical Hydrogen Production

ECS Meeting Abstracts ◽

10.1149/ma2014-02/8/574 ◽

2014 ◽

Keyword(s):

Hydrogen Production ◽

Wide Bandgap ◽

Copper Chalcopyrite ◽

Photoelectrochemical Hydrogen Production

Download Full-text

Hydrogen production characteristics of photoheterotrophic Rubrivivax gelatinosus L31

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2007.12.001 ◽

2008 ◽

Vol 33 (3) ◽

pp. 974-980 ◽

Cited By ~ 32

Author(s):

R LI

Keyword(s):

Hydrogen Production ◽

Rubrivivax Gelatinosus ◽

Production Characteristics

Download Full-text

Thermoelectric Properties of Carbon Nanotubes

Energies ◽

10.3390/en12234561 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4561 ◽

Cited By ~ 6

Author(s):

Nguyen T. Hung ◽

Ahmad R. T. Nugraha ◽

Riichiro Saito

Keyword(s):

Carbon Nanotubes ◽

Figure Of Merit ◽

Waste Heat ◽

Quantum Confinement Effect ◽

Electrical Energy ◽

High Seebeck Coefficient ◽

Te Material ◽

P Type ◽

State Device ◽

Solid State Device

Thermoelectric (TE) material is a class of materials that can convert heat to electrical energy directly in a solid-state-device without any moving parts and that is environmentally friendly. The study and development of TE materials have grown quickly in the past decade. However, their development goes slowly by the lack of cheap TE materials with high Seebeck coefficient and good electrical conductivity. Carbon nanotubes (CNTs) are particularly attractive as TE materials because of at least three reasons: (1) CNTs possess various band gaps depending on their structure, (2) CNTs represent unique one-dimensional carbon materials which naturally satisfies the conditions of quantum confinement effect to enhance the TE efficiency and (3) CNTs provide us with a platform for developing lightweight and flexible TE devices due to their mechanical properties. The TE power factor is reported to reach 700–1000 W / m K 2 for both p-type and n-type CNTs when purified to contain only doped semiconducting CNT species. Therefore, CNTs are promising for a variety of TE applications in which the heat source is unlimited, such as waste heat or solar heat although their figure of merit Z T is still modest (0.05 at 300 K). In this paper, we review in detail from the basic concept of TE field to the fundamental TE properties of CNTs, as well as their applications. Furthermore, the strategies are discussed to improve the TE properties of CNTs. Finally, we give our perspectives on the tremendous potential of CNTs-based TE materials and composites.

Download Full-text