Atomic-Scale Model and Electronic Structure of CuO/CHNHPbI Interfaces in Perovskite Solar Cells.

Cuprous oxide has been conceived as a potential alternative to traditional organic hole-transport layers in hybrid halide perovskite-based solar cells. Device simulations predict record efficiencies using this semiconductor, but experimental results do not yet show this trend. More detailed knowledge about the CuO/perovskite interface is mandatory to improve the photoconversion efficiency.

Band Alignment of the CuGaS Chalcopyrite Interfaces Studied by First-Principles Calculations.

The valence and conduction band offsets for both polar and nonpolar CuGaS/CuAlSe and CuGaS/ZnSe interfaces were studied here by the state-of-the-art first-principles calculations. Using the hybrid functional calculations, we show that the CuGaS/CuAlSe and CuGaS/ZnSe heterostructures in all interfaces form type II band alignment. The difference of valence and conduction band offsets is mainly due to lattice mismatch, generating stress in the interface and affecting the electronic properties of each material; meanwhile, the polarity configuration does not play an important role in these values.

Transition Metal-Hyperdoped InP Semiconductors as Efficient Solar Absorber Materials.

This work explores the possibility of increasing the photovoltaic efficiency of InP semiconductors through a hyperdoping process with transition metals (TM = Ti, V, Cr, Mn). To this end, we investigated the crystal structure, electronic band and optical absorption features of TM-hyperdoped InP (TM@InP), with the formula TMxIn1-xP (x = 0.03), by using accurate ab initio electronic structure calculations.

Thermoelectric Properties of Doped-CuSbSe Compounds: A First-Principles Insight.

This work reports the first systematic study of the effects of substitutional doping on the transport properties and electronic structure of CuSbSe. To this end, the electronic structures and thermoelectric parameters of CuSbSe and CuSbM Se (M = Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, Bi) were systematically investigated by using density functional theory and the Boltzmann semiclassical transport theory. Substitutional doping at Sb site with IIIA (M = Al, Ga, In, Tl) and IVA (M = Si, Ge, Sn, Pb) elements considerably increases the hole carrier concentration and consequently the electrical conductivity, while doping with M = Bi would be adequate to provide high S values.

Author Correction: Influence of chromium hyperdoping on the electronic structure of CHNHPbI perovskite: a first-principles insight.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Influence of chromium hyperdoping on the electronic structure of CHNHPbI perovskite: a first-principles insight.

Organic-inorganic hybrid halide perovskites compounds are emerging as new materials with great potential for efficient solar cells. This paper explores the possibility of increasing their photovoltaic efficiency through sub-bandgap absorption by way of the in gap band (IGB) concept. Thus, we assess the formation of an in gap band as well as its effect on the absorption features of Organic-inorganic hybrid halide perovskites CHNHPbI (MAPI).

Analysis of SnS2 hyperdoped with V proposed as efficient absorber material.

Intermediate-band materials can improve the photovoltaic efficiency of solar cells through the absorption of two subband-gap photons that allow extra electron-hole pair formations. Previous theoretical and experimental findings support the proposal that the layered SnS2 compound, with a band-gap of around 2 eV, is a candidate for an intermediate-band material when it is doped with a specific transition-metal. In this work we characterize vanadium doped SnS2 using density functional theory at the dilution level experimentally found and including a dispersion correction combined with the site-occupancy-disorder method.

V-doped SnS2: a new intermediate band material for a better use of the solar spectrum.

Intermediate band materials can boost photovoltaic efficiency through an increase in photocurrent without photovoltage degradation thanks to the use of two sub-bandgap photons to achieve a full electronic transition from the valence band to the conduction band of a semiconductor structure. After having reported in previous works several transition metal-substituted semiconductors as able to achieve the electronic structure needed for this scheme, we propose at present carrying out this substitution in sulfides that have bandgaps of around 2.0 eV and containing octahedrally coordinated cations such as In or Sn.

Energetics of formation of TiGa3As4 and TiGa3P4 intermediate band materials.

Using density functional theory quantum methods, total energy values and vibrational properties have been computed, and thermodynamic properties evaluated, for Ti-substituted GaAs and GaP, proposed as candidates for intermediate band photovoltaic cells. The calculations predict that the formation of these materials from the binary compounds implies an increase in total energy (that is ascribed largely to the change in coordination undergone by Ti, from six-fold to four-fold), and thus phase separation rather than mixed compound formation would be favored. However, the mentioned increase is not larger (for the arsenide case it is actually smaller) than that predicted for Mn-substituted GaAs, a material which has been experimentally made, and therefore the obtention of these Ti-substituted materials is expected to be feasible as well.