Limiting efficiency of an intermediate band solar cell under a terrestrial spectrum

Abstract

The limiting efficiency of an intermediate band (IB) solar cell under the terrestrial AM1.5 spectrum was calculated by detailed balance for various concentration levels. The results show four energy gap combinations giving similar limiting efficiencies. This is in contrast to the more studied case of an IB solar cell under a blackbody spectrum where a single optimum combination is found. A design with a subenergy gap of ∼0.57eV is found to be viable, leading to the conclusion that the design space for an IB solar cell is larger when under the AM1.5 spectrum than when under a Blackbody spectrum.

Multilayered InGaN/GaN structure vs. single InGaN layer for solar cell applications: A comparative study

“…To obtain this high efficiency, InGaN layers with a large In content are required. For instance, a solar cell with only one InGaN junction containing 68% indium, can achieve 30% efficiency [2]. In addition, despite a high absorption coefficient, InGaN layer thicknesses >100 nm are required for the absorption of more than 90% of the incident above-bandgap light [3].…”

Methodology for vetting heavily doped semiconductors for intermediate band photovoltaics: A case study in sulfur-hyperdoped silicon

“…[2][3][4][5] The introduction of an additional, intermediate band of electronic levels within the band gap could dramatically increase device current through a two-photon process while only resulting in small losses in operating voltage. 6 Theoretical investigations 2,7,8 indicate that intermediate-band solar cells can achieve efficiencies over 60%, though no intermediate-band devices have been demonstrated with efficiencies exceeding the Shockley-Queisser limit. Experimental work has primarily focused on three material systems: highly mismatched alloys, [9][10][11][12][13][14] quantum dot structures, [15][16][17] and impurity-band materials.…”

Absorption characteristics of a quantum dot array induced intermediate band: Implications for solar cell design

“…A promising proposal is the intermediate band SC ͑IBSC͒, 3,4 for which, under ideal conditions, an efficiency of 63% can be achieved with a degree of flexibility in the value of the energy gaps and the IB position. 5 The higher efficiency is due to the fact that additional absorption, from valence band ͑VB͒ states to the IB and from the IB to the conduction band ͑CB͒ states, allows two photons with energies below the energy gap of the barrier material to be harvested in generating one electron-hole pair, in addition to those generated by direct VB-CB transitions. In this way the IBSC overcomes the problem of increasing the SC photocurrent without degrading its voltage.…”