Premium
Transparent Cuprous Oxide Photocathode Enabling a Stacked Tandem Cell for Unbiased Water Splitting
Author(s) -
Dias Paula,
Schreier Marcel,
Tilley S. David,
Luo Jingshan,
Azevedo João,
Andrade Luísa,
Bi Dongqin,
Hagfeldt Anders,
Mendes Adélio,
Grätzel Michael,
Mayer Matthew T.
Publication year - 2015
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201501537
Subject(s) - photocathode , tandem , materials science , optoelectronics , transmittance , opacity , stack (abstract data type) , water splitting , oxide , photon , band gap , photoelectrochemical cell , optics , photocatalysis , electrode , electrolyte , physics , computer science , chemistry , quantum mechanics , metallurgy , composite material , programming language , electron , biochemistry , catalysis
Photoelectrochemical water splitting represents an attractive method of capturing and storing the immense energy of sunlight in the form of hydrogen, a clean chemical fuel. Given the large energetic demand of water electrolysis, and the defined spectrum of photons available from incident sunlight, a two absorber tandem device is required to achieve high efficiencies. The two absorbers should be of different and complementary bandgaps, connected in series to achieve the necessary voltage, and arranged in an optical stack configuration to maximize the utilization of sunlight. This latter requirement demands a top device that is responsive to high‐energy photons but also transparent to lower‐energy photons, which pass through to illuminate the bottom absorber. Here, cuprous oxide (Cu 2 O) is employed as a top absorber component, and the factors influencing the balance between transparency and efficiency toward operation in a tandem configuration are studied. Photocathodes based on Cu 2 O electrodeposited onto conducting glass substrates treated with thin, discontinuous layers of gold achieve reasonable sub‐bandgap transmittance while retaining performances comparable to their opaque counterparts. This new high‐performance transparent photocathode is demonstrated in tandem with a hybrid perovskite photovoltaic cell, resulting in a full device capable of standalone sunlight‐driven water splitting.