Holistic Thermo-Optical Design of Laminate Layers for Halide Perovskite Photovoltaic Windows.

Though power conversion is an important metric for photovoltaic windows, it must be balanced with visible transmittance, aesthetics (color and haze), and thermal performance. Optical properties are often reported, but thermal performance is typically neglected entirely in photovoltaic window design. Here, we introduce the strategy of using laminate layers to improve the thermo-optical performance of perovskite-based photovoltaic insulating glass units.

Crystalline Si Surface Passivation with Nafion for Bulk Defects Detection with Electron Paramagnetic Resonance.

In monocrystalline Si (c-Si) solar cells, identification and mitigation of bulk defects are crucial to achieving a high photoconversion efficiency. To spectroscopically detect defects in the c-Si bulk, it is desirable to passivate the surface defects. Passivation of the c-Si surface with dielectrics such as AlO and SiN requires deposition at elevated temperatures, which can influence defects in the bulk.

3D and Multimodal X-Ray Microscopy Reveals the Impact of Voids in CIGS Solar Cells.

Small voids in the absorber layer of thin-film solar cells are generally suspected to impair photovoltaic performance. They have been studied on Cu(In,Ga)Se cells with conventional laboratory techniques, albeit limited to surface characterization and often affected by sample-preparation artifacts. Here, synchrotron imaging is performed on a fully operational as-deposited solar cell containing a few tens of voids.

Effect of Surface Texture on Pinhole Formation in SiO-Based Passivated Contacts for High-Performance Silicon Solar Cells.

High-efficiency silicon solar cells rely on some form of passivating contact structure to reduce recombination losses at the crystalline silicon surface and losses at the metal/Si contact interface. One such structure is polycrystalline silicon (poly-Si) on oxide, where heavily doped poly-Si is deposited on a SiO layer grown directly on the crystalline silicon (c-Si) wafer. Depending on the thickness of the SiO layer, the charge carriers can cross this layer by tunneling (<2 nm SiO thickness) or by direct conduction through disruptions in the SiO, often referred to as pinholes, in thicker SiO layers (>2 nm).

Directly Linking Low-Angle Grain Boundary Misorientation to Device Functionality for GaAs Grown on Flexible Metal Substrates.

A new growth method to make highly oriented GaAs thin films on flexible metal substrates has been developed, enabling roll-to-roll manufacturing of flexible semiconductor devices. The grains are oriented in the <001> direction with <1° misorientations between them, and they have a comparable mobility to single-crystalline GaAs at high doping concentrations. At the moment, the role of low-angle grain boundaries (LAGBs) on device performance is unknown.

Optical and Structural Properties of High-Efficiency Epitaxial Cu(In,Ga)Se Grown on GaAs.

Photovoltaic devices based on Cu(In,Ga)Se (CIGS) typically employ polycrystalline thin films as the absorber layer. This is because, to date, the highest conversion efficiencies have been attained with polycrystalline CIGS films. Recently, Nishinaga et al.

Effect of Crystallographic Orientation and Nanoscale Surface Morphology on Poly-Si/SiO Contacts for Silicon Solar Cells.

High-efficiency crystalline silicon (Si) solar cells require textured surfaces for efficient light trapping. However, passivation of a textured surface to reduce carrier recombination is difficult. Here, we relate the electrical properties of cells fabricated on a KOH-etched, random pyramidal-textured Si surface to the nanostructure of the passivated contact and the textured surface morphology.