Device Performance of the Mott InsulatorLaVO3as a Photovoltaic Material

Abstract

Searching for solar-absorbing materials containing earth-abundant elements with chemical stability is of critical importance for advancing photovoltaic technologies. Mott insulators have been theoretically proposed as potential photovoltaic materials. In this paper, we evaluate their performance in solar cells by exploring the photovoltaic properties of Mott insulator LaVO 3 (LVO). LVO films show an indirect band gap of 1.08 eV as well as strong light absorption over a wide wavelength range in the solar spectrum. First-principles calculations on the band structure of LVO further reveal that the d-d transitions within the upper and lower Mott-Hubbard bands and p-d transitions between the O 2p and V 3d band contribute to the absorption in visible and ultraviolet ranges, respectively. Transport measurements indicate strong carrier trapping and the formation of polarons in LVO. To utilize the strong light absorption of LVO and to overcome its poor carrier transport, we incorporate it as a light absorber in solar cells in conjunction with carrier transporters and evaluate its device performance. Our complementary experimental and theoretical results on such prototypical solar cells made of Mott-Hubbard transition-metal oxides pave the road for developing light-absorbing materials and photovoltaic devices based on strongly correlated electrons. PHYSICAL REVIEW APPLIED 3, 064015 (2015) 2331-7019=15=3(6)=064015 (15) 064015-1

Many-body recombination in photoexcited insulating cuprates

“…By contrast, interactions may enhance such recombination in antiferromagnetic insulators, by opening new magnetic channels for decay [9,10]. Beyond these two-particle recombination processes, interactions may also enhance three-particle processes such as Auger recombination and its inverse process, impact ionization [11][12][13][14][15][16][17].…”

Hund excitations and the efficiency of Mott solar cells

“…It has a direct band-gap of about 1.1 eV and an internal electric field due to the polar nature of the LVO layers. Experimentally, however, the devices fabricated so far have shown a low efficiency due to a low mobility of the photo-carriers [7,8]. Also theoretically, it has been argued that the strong internal fields of these structures may localize charge carriers [9].…”

Preparation and characterization of narrow bandgap ferroelectric (K,Ba)(Ni,Nb)O3−δ films for mesoporous all-oxide solar cells

“…The hole mobility of p-type NiO is 25 cm 2 V −1 s −1 . It is regarded as one of the excellent inorganic HTMs for dye-sensitized and FE-based PV devices [29][30][31][32]. .…”