Conventional p-CuInSe2 absorbers for solar cells have been homogenously synthesized using multi-step process despite a narrow crystal phase region in the phase diagram and the existence of various secondary phases. In contrast, here we propose artificially-designed heterophasic blended copper indium selenide compounds for water splitting photoanodes using a simple one-step annealing synthetic process where the electrodeposited metal precursors were directly annealed with Se vapor injection and without additional intermediate steps. The resultant product is revealed to possess a novel “phase-blended structure” comprising two phases of p-type CuInSe2 and n-type CuIn3Se5 crystals. The CuInSe2 nanoparticles with a higher Cu fraction are three-dimensionally (3D) embedded in the n-type CuIn3Se5 matrix, which has been verified by various analysis methods such as X-ray diffraction, transmission electron microscopy, and capacitance-voltage curve. The average diameter of the CuInSe2 nanoparticles is 66.8 nm and the interval between the nanoparticles in the CuIn3Se5 matrix is 67.6 nm. Consequently, the phase-blended structure photoabsorber exhibits a remarkably enhanced anodic photocurrent of 12.7 mA/cm2 at 1.23 V versus the reversible hydrogen electrode. The considerably enhanced photocurrent gain of the phase-blended structure photoanode is attributed to the excellent charge separation facilitated by the built-in potential generated from the 3D p-n junction.
|Number of pages||10|
|Publication status||Published - 2018 Apr|
Bibliographical noteFunding Information:
This research on synthesis and water splitting performed by H.K.Cho was supported by Samsung Research Funding & Incubation Center of Samsung Electronics under Project Number SRFC-MA1702-06 . The work on the preparation of metal precursors by J.S.Kim was supported by The Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (Grant No. 20154030200870 ).
© 2018 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering