With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses key factors responsible for the success of the classic dopant-diffused silicon homojunction solar cell. Next it analyzes two archetypal high-efficiency device architectures – the interdigitated back-contact silicon cell and the silicon heterojunction cell – both of which have demonstrated power conversion efficiencies greater than 25%. Last, it gives an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrier-selective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic–inorganic perovskite materials.

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High-efficiency crystalline silicon solar cells: status and perspectives

As a next generation of detection technology, terahertz technology is very promising. In this work, a highly efficient terahertz wave absorber based on 3D graphene foam (3DG) is first reported. Excellent terahertz absorption property at frequency ranging from 0.1 to 1.2 THz is obtained owing to faint surface reflection and enormous internal absorption. By precise control of the constant properties for 3DG, the reflection loss (RL) value of 19 dB is acquired and the qualified frequency bandwidth (with RL value over 10 dB) covers 95% of the entire measured bandwidth at normal incidence, which far surpasses most reported materials. More importantly, the terahertz absorption performance of 3DG enhances obviously with increasing the incidence while majority of materials become invalid at oblique incidence, instead. At the incidence of 45°, the maximum RL value increases 50% from 19 to 28.6 dB and the qualified frequency bandwidth covers 100% of the measured bandwidth. After considering all core indicators involving density, qualified bandwidth, and RL values, the specific average terahertz absorption (SATA) property is investigated. The SATA value of 3DG is over 3000 times higher than those of other materials in open literatures.

Ultra-Broadband Wide-Angle Terahertz Absorption Properties of 3D Graphene Foam

The role of dimensionality on the electronic performance of thermoelectric devices is clarified using the Landauer formalism, which shows that the thermoelectric coefficients are related to the transmission, T(E), and how the conducing channels, M(E), are distributed in energy. The Landauer formalism applies from the ballistic to diffusive limits and provides a clear way to compare performance in different dimensions. It also provides a physical interpretation of the "transport distribution," a quantity that arises in the Boltzmann transport equation approach. Quantitative comparison of thermoelectric coefficients in one, two, and three dimension shows that the channels may be utilized more effectively in lower-dimensions. To realize the advantage of lower dimensionality, however, the packing density must be very high, so the thicknesses of the quantum wells or wires must be small. The potential benefits of engineering M(E) into a delta-function are also investigated. When compared to a bulk semiconductor, we find the potential for ~50 % improvement in performance. The shape of M(E) improves as dimensionality decreases, but lower dimensionality itself does not guarantee better performance because it is controlled by both the shape and the magnitude of M(E). The benefits of engineering the shape of M(E) appear to be modest, but approaches to increase the magnitude of M(E) could pay large dividends.

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Influence of Dimensionality on Thermoelectric Device Performance

Polycrystalline silicon thin-film solar cells: Status and perspectives

Non-vacuum processed next generation thin film photovoltaics: Towards marketable efficiency and production of CZTS based solar cells

Crystalline Si (c-Si) technology is dominating the photovoltaics market. These modules are nonetheless still relatively expensive, in particular because of the costly silicon wafers, which require large thickness mostly to ease handling. Thin-film technologies, on the other hand, use much less active material, exhibit a much lower production cost per unit area, but achieve an efficiency still limited on module level, which increases the total system costs. A meet-in-the-middle is possible and is the object of this paper. The development of c-Si thin-foil modules is presented: first, the fabrication of the active material on a glass module and then the processing of the Si foils into solar cells, directly on module level. The activity of IMEC in this area is put into perspective with regard to worldwide research results. It appears that great opportunities are offered to this cell concept, although some challenges still need to be tackled before cost-effective and reliable industrial production can be launched. Copyright © 2012 John Wiley & Sons, Ltd.

Crystalline thin‐foil silicon solar cells: where crystalline quality meets thin‐film processing

Kapton-derived carbon as efficient terahertz absorbers

https://iopscience.iop.org/article/10.1088/2053-1591/aad617/pdf

Srisaran Venkatachalam

Papers

Crystalline thin‐foil silicon solar cells: where crystalline quality meets thin‐film processing

Kapton-derived carbon as efficient terahertz absorbers

Ricinus communis fiber as potential reinforcement for lightweight polymer composites

Properties of n-type polycrystalline silicon solar cells formed by aluminium induced crystallization and CVD thickening

Pyrolytic conversion of organopolysiloxanes