Analytical Model of InP QWs for Efficiency Improvement in GaInP/Si Dual Junction Solar Cell

Abstract

Quantum wells (QWs) are proven to enhance the short circuit current and voltage preservation measures help in efficiency enhancement with little degradation of open circuit voltage . Herein, an integrated GaInP/Si dual junction solar cell is proposed by incorporating the QWs in the top cell and carrier‐selective passivated contact at the bottom cell of the design. The QW increases the photon absorption of sub‐bandgap energies, buffer layer reduces the misfits between the lattice mismatched layers, and passivation mechanism improves the overall efficiency. Increasing the number of QWs increases the depletion width of QW region. This reduces the carrier lifetime () and increases the recombinations in the QW region. It results in the reduction in passivation quality and, therefore, reduces the open circuit voltage (). QW strain balancing and measures to reduce the threading dislocations has been considered. Also, the wide bandgap GaInP tunnel junction along with highly doped GaAs tunnel junction has been analyzed to observe the parasitic effect. The GaInP/Si‐integrated model achieves efficiency of 33.39% when the QWs are incorporated in the top cell. The effect of wide bandgap tunnel junction is also evaluated using GaInP tunnel junction.

Optimization of a‐Si Thin‐Film Solar‐Cell Performance with Passivation and c‐Si Cap Layer

“…the passivation and absorption layer plays important role in enhancing the and of the Cell. [ 24,25 ] A comparison table of the designed a‐Si TFSC with simple design, with the a‐Si passivation layer and with a‐Si passivation and c‐Si cap layer is given in Table 1 and shown in Figure 5.…”

GaAs0.95P0.05 single junction solar cell with InP QW in p-i-n region for sub-bandgap photon absorption

“…But due to the recombination in the barrier region and very less bandgap energy difference between the base material and QW material, the short circuit current is not increased, moreover very small reduction in the current density is noted in table 3. Interestingly, the symmetrical sizing of the QW and barrier region performs the voltage preservation [2,8,28,29].…”

“…The carrier escapes the barrier region of GaInP due to the thermionic emission process. The explanations are elaborated in the previously reported literatures[2,3,8,28,29].…”

“…The performance of the compound material solar cell can be improved beyond the theoretical limit by implementing one of the above-mentioned techniques [1]. The researchers are working on the utilization of sub-bandgap photon energy in the sub nano region in the form of quantum wells and nano wires to improve the solar cell spectrum utilization in the range of 300 nm to 3.4 μm wavelength of spectrum [2,3]. This leads to the utilization of the binary, ternary and quaternary compound materials from the IIIrd and Vth group of the periodic tables.…”

“…The optimization of the cell structure and use of nano structure leads to achieve higher efficient solar cell [24][25][26][27]. The InP as quantum well (QW) material along with GaInP material have been utilized in the p-i-n region of the GaInP cell as single junction and dual junction material, for the absorption of the sub-bandgap photon energy [2,3,8,28,29].…”