arXiv subjects

Olivier Dupré

Publications and source records attributed to Olivier Dupré.

3 recordsLinked to original sources

arXiv2021

Optimized Design of Silicon Heterojunction Solar Cells for Field Operating Conditions

Solar modules are currently characterized at standard test conditions (STC), defined at 1000W/m2 and 25 °C. However, solar modules in actual outdoor operating conditions typically operate at lower illumination and higher temperature than STC, which significantly affects their performance ratio (average harvesting efficiency over efficiency in STC). Silicon heterojunction (SHJ) technology displays both good temperature coefficient and good low-illumination performances, leading to outstanding performance ratios. We investigate here SHJ solar cells that use a-SiCx(n) layer as front doped layer with different carbon contents under different climates conditions. Adding carbon increases transparency but also resistive losses at room temperature (compared with carbon-free layers), leading to a significant decrease in efficiency at STC. We demonstrate that despite this difference at STC, the difference in energy harvesting efficiency is much smaller in all investigated climates. Furthermore, we show that a relative gain of 0.4 to 0.8 percent in harvesting efficiency is possible by adding a certain content of carbon in the front (n) layer, compared with carbon-free cells optimized for STC.

physics.app-ph↗

arXiv2015

Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

The impacts of radiative, electrical and thermal losses on the power output enhancement of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten emitter, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the absorption bandgap. In a nano-TPV power generator cooled by convection with a fluid at 293 K and a heat transfer coefficient of 10^4 Wm^-2K^-1, power output enhancements of 4.69 and 1.89 are obtained for the tungsten and Drude radiators, respectively, when a realistic vacuum gap thickness of 100 nm is considered. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output is determined. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses.

cond-mat.mtrl-sci↗

arXiv2013

TASC-1D-cSi: a simulation tool to scrutinize the thermal impacts on the performances of crystalline silicon solar cells

The capabilities of a simulation tool for the in-depth analysis of the thermal impacts on the performances of solar cells are described. TASC-1D (Thermal Analysis of Solar Cells - 1D, version cSi) solves the coupled electrical, radiative and thermal transport problems for a crystalline silicon cell, as a function of irradiation and thermal conditions. In addition to the electrical outputs that are obtained with the existing simulation tools, it provides the cell equilibrium temperature as well as the spatial and spectral distributions of many relevant quantities. The physical modeling and associated numerical solution techniques are summarized. Result cases with a prescribed cell temperature demonstrate that the code performs well, is able to provide valuable information on the quantum efficiency and power loss mechanisms, and is capable of handling diffuse irradiations. The intricate correlation between thermal sources and optical-electrical losses is discussed. The other cases include the solution of the heat transfer problem and analyses are conducted on the cell operating temperature and efficiency as a function of the thermal conditions. This simulation tool is likely to allow new optimizations of photovoltaic cells that include a thermal criterion in addition to the optical and electrical criteria.

cond-mat.mtrl-sci↗