Maximal Efficiencies in New Single GaAs(1−x) P(x) - Alloy Junction Solar Cells at 300 K

Abstract

In single n+(p+) − p(nn) [X(x) ≡ GA1−xPx]-alloy junction solar cells at 300 K, 0 ≤ xx ≤ 1, by basing on the same physical model and the same treatment method, as those used in our recent works (Van Cong, 2024), we will also investigate the highest (or maximal) efficiencies, ηImax .(IImax.) at the open circuit voltageVos(= Vos1 (os2 ),according to highest hot reservoir temperatures TH(K), obtained from the Carnot efficiency theorem, which was demonstrated by the use of the entropy law. Here, some concluding remarks are given in the following. (i)-First, with increasing x=(0, 0.5, 1), from Table 3, obtained for the single n+ − p X(x)-alloy junction solar cells, and for given rSn(Cd)-radius, for example, one obtains: ηImax (↗)= 31.18%, 33.495%, 35.99%, according to TH(K) = 435.9, 451.1, 468.7, at Vos (V) = 1.07, 1.06, 1.05, respectively. (ii)- Secondly, with increasing x=(0, 0.5, 1), from Table 5, obtained for the single p+ − n X(x)-alloy junction solar cells, and for given rCd(Sn)-radius, for example, one gets: ηηIImax (↘)= 33.05%, 31.95%, 31.37%, according to TH(K) = 448.0, 440.9, 437.1, at Vos (V)[>Vos(V)] = 1.20, 1.15, 1.12, respectively, suggesting that such ηImax .(IImax .)-and-TH variations dependon Vos(V)[> Vos (V)] − values. Then, in particular, as given in Table 3, for x = 0 and (rda ) =(pt), one gets: ηI =23.48 % and 29.76 % at Vos= 0.98 V and 1.1272 V, respectively, which can be compared with the corresponding results obtained by Moon et al. (2016) and Green et al. (2022) for the single-junction GaAs thin-film solar cell, 22.08 % and 29.71 %, with relative deviations in absolute values, 6.34 % and 0.17 %. Finally, one notes that, in order to obtain the highest efficiencies, the single GaAs1−x Px-alloy junction solar cells could be chosen rather than the single crystalline GaAs-junction solar cell.