III–V nanowire photovoltaics: Review of design for high efficiency

Abstract

1 Introduction Global energy demand is predicted to exceed 30 TW by 2050, about double the present value [1]. This predicament, known as the TeraWatt challenge, and concern over anthropogenic climate change, resource availability ("peak energy") and energy security have all increased the interest in renewable energy (hydroelectric, wind, solar, geothermal and biomass) [2]. One of the most promising renewable energy technologies is solar photovoltaics (PV) which convert sunlight directly into electrical energy. Although the resource potential of PV is enormous, it currently constitutes a small fraction (<1%) of global energy supply [2]. One of the main factors limiting the widespread adoption of PV is its low energy density, low efficiency, and relatively high cost in comparison to other energy technologies. This means that current PV technology can only compete in areas of high insolation or by government incentives such as feed-in tariff programs.One of the most relevant metrics for PV devices is the power conversion efficiency (PCE); that is, the efficiency with which sunlight can be converted to electrical power. A significant effort in PV research today aims to improve PCE while simultaneously reducing (or, at least, not significantly impacting) production cost. The vast majority of

Conductive-probe atomic force microscopy as a characterization tool for nanowire-based solar cells

“…The needle-like morphology of NWs is also advantageous for the extraction of the photo-generated carriers via a radial p-n junction design [8,9]. Today, experimental efficiencies of NW ensemble solar cells are still lower than the record values for planar solar cells [10][11][12].…”

Strategies to obtain pattern fidelity in nanowire growth from large-area surfaces patterned using nanoimprint lithography

“…NW solar cell research is rapidly evolving [4] because efficient light trapping by these antenna-like structures has been theoretically predicted [5] and experimentally proven [6,7]. In particular, theoretical modeling based on wave optics has predicted diameter-dependent resonant light-trapping in NW arrays [8][9][10], which allows bulk-like photo-current generation in NW-based solar cells with just a fraction of the material consumption in comparison with thin film solar cells of the same material [3].…”

“…In particular, theoretical modeling based on wave optics has predicted diameter-dependent resonant light-trapping in NW arrays [8][9][10], which allows bulk-like photo-current generation in NW-based solar cells with just a fraction of the material consumption in comparison with thin film solar cells of the same material [3]. To achieve high-efficiency NW-based solar cells, high quality NW growth from patterned substrates is required [4]. Substrate patterning for NW growth is most commonly achieved using electron beam lithography (EBL) [11] or nanoimprint lithography (NIL) [12].…”

Welcome to rrl solar – more photovoltaics and energy research in pss (RRL)

“…Latest highlights have been topical reviews on III-V nanowire PV [5] (as part of our Focus issue on Semiconductor Nanowires forthcoming in October) and luminescence inline characterization of silicon [6].…”