About the Ultimate Efficiency of Interference Binary Codes

The digital representation of various signals allows, at the subsequent stages of their transmission, to apply correction codes that provide protection against possible errors arising from the action of interference in the communication channel. At the same time, it is important that, with the required correcting ability, these codes have the maximum possible speed. The article presents the results of calculations for linear codes, showing their really achievable limiting capabilities.

Efficiency limits of concentrating spectral-splitting hybrid photovoltaic-thermal (PV-T) solar collectors and systems

Spectral splitting is an approach to the design of hybrid photovoltaic-thermal (PVT) collectors that promises significant performance benefits. However, the ultimate efficiency limits, optimal PV cell materials and optical filters of spectral-splitting PVT (SSPVT) collectors remain unclear, with a lack of consensus in the literature. We develop an idealized model of SSPVT collectors and use this to determine their electrical and thermal efficiency limits, and to uncover how these limits can be approached through the selection of optimal PV cell materials and spectral-splitting filters. Assuming that thermal losses can be minimized, the efficiency limit, optimal PV material and optimal filter all depend strongly on a coefficient w, which quantifies the value of the delivered thermal energy relative to that of the generated electricity. The total (electrical plus thermal) efficiency limit of SSPVT collectors increases at higher w and at higher optical concentrations. The optimal spectral-splitting filter is defined by sharp lower- and upper-bound energies; the former always coincides with the bandgap of the cell, whereas the latter decreases at higher w. The total effective efficiency limit of SSPVT collectors is over 20% higher than those of either standalone PV modules or standalone ST collectors when w is in the range from 0.35 to 0.50 and up to 30% higher at w ≈ 0.4. This study provides a method for identifying the efficiency limits of ideal SSPVT collectors and reports these limits, along with guidance for selecting optimal PV materials and spectral-splitting filters under different conditions and in different applications.

Effect of Different Minority Carrier Lifetime of Multicrystalline Wafer on Solar Cell Performance

<p>In thisarticle, a study of the effect of different minority carrier lifetime (τ) of wafers on solar cell performance in a conventional industrial production line has been carried out. The results clearly showed that the ultimate efficiency of the solar cells made by wafers of 1μs &lt;τ&lt;1.2μs and 1.2μs &lt;τ&lt;1.5μs is much higher than that of solar cells made by wafers of τ&lt;1μs. The gap of both is about 0.38%–0.53%. Differently, there is no significant difference between wafers of 1μs&lt;τ&lt;1.2μs and 1.2μs &lt;τ&lt;1.5μs. The results obtained are useful when the solar cell companies establish original wafers test standard in industry.</p>

Theoretical efficiency limits of ideal coloured opaque photovoltaics

Theoretical analysis connecting photovoltaics and colorimetry reveals the ultimate efficiency limits of colorful single-band-gap solar cells and modules.