Three-Bandgap Absolute Quantum Efficiency in GaSb/GaAs Quantum Dot Intermediate Band Solar Cells

Ramiro, I.; Antolín, E.; Hwang, Jiann Loung; Teran, Alan; Martin, Andrew J.; Linares, P.G.; Millunchick, Joanna Mirecki; Phillips, Jamie; Martı́, Antonio; Ĺuque, A.

doi:10.1109/jphotov.2016.2637658

Cited by 22 publications

(21 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The method for converting the measured photocurrent into QE or SR is detailed in Ref. [36]. For the photovoltage measurements, only the 1.32 eV source was employed; samples were connected to a voltage amplifier; and the chopping frequency was 6 Hz.…”

Section: Samples and Methodsmentioning

confidence: 99%

“…In Ref. [36] we reported spectrally resolved two-photon photocurrent (process (I)) in our GaSb/GaAs QDs. In Figure 4a, we extend those results by further increasing the light intensity of the photon flux.…”

Section: Type-ii Hole-based Ibscmentioning

confidence: 99%

“…Details of the experimental set-up can be found in Refs. [7] and [36], and in the Samples and Methods Section. The general principle is that the sample can be simultaneously illuminated by two monochromatic light beams identified as ph1 and ph2.…”

Section: Type-ii Hole-based Ibscmentioning

confidence: 99%

“…In Refs. [35,36] and [34], process (I) and (II), respectively, were demonstrated. All those works employed GaSb/GaAs QDs as the IB material.…”

mentioning

confidence: 93%

“…It has been suggested that type-II (staggered band lineup, Figure 2) QDs may be advantageous for the implementation of IBSCs, since they would not cause effective bandgap narrowing [29]. In the past years, various experimental works on type-II QD-IBSCs have been reported [31][32][33][34][35][36]. In Refs.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Analysis of the intermediate-band absorption properties of type-II GaSb/GaAs quantum-dot photovoltaics

et al. 2017

View full text Add to dashboard Cite

Quantum-dot (QD) intermediate-band (IB) materials are regarded as promising candidates for high-efficiency photovoltaics. The sequential two-step two-photon absorption processes that take place in these materials have been proposed to develop high-efficiency solar cells and infrared (IR) photodetectors. In this work, we experimentally and theoretically study the interrelation of the absorptivity with transitions of carriers to and from the IB in type II GaSb/GaAs QD devices. Our devices exhibit three optical bandgaps with: E L =0.49 eV, E H =1.02 eV and E G =1.52 eV, with the IB located 0.49 eV above the valence band. These values are well supported by semi-empirical calculations of the QDs electronic structure. Through intensity-dependent twophoton photocurrent experiments, we are able to vary the filling state of the IB, thus modifying the absorptivity of the transitions to and from this band. By filling the IB with holes via E=1.32 eV or E=1.93 eV monochromatic illumination, we demonstrate an increase in the E L-related absorptivity of more than two orders of magnitude and a decrease in the E H-related absorptivity of one order of magnitude. The anti-symmetrical evolution of those absorptivities is quantitatively explained by a photo-induced shift of the quasi-Fermi level of the IB. Furthermore, we report the observation of a two-photon photovoltage; i. e., the contribution of sub-bandgap two-photon absorption to increase the open-circuit voltage of solar cells. We find that the generation of the twophoton photovoltage is related, in general, to the production of a two-photon photocurrent. However, while photons with energy close to E L participate in the production of the two-photon photocurrent, they are not effective in the production of a two-photon photovoltage. We also report the responsivity of GaSb/GaAs QD devices performing as optically triggered photodetectors. These devices exhibit an amplification factor of almost 400 in the IR spectral region. This high value is achieved by minimizing-via doping-the absorptivity in the IR range of the QDs under equilibrium conditions. I. INTRODUCTION

show abstract

Section: Samples and Methodsmentioning

confidence: 99%

Section: Type-ii Hole-based Ibscmentioning

confidence: 99%

Section: Type-ii Hole-based Ibscmentioning

confidence: 99%

“…In Refs. [35,36] and [34], process (I) and (II), respectively, were demonstrated. All those works employed GaSb/GaAs QDs as the IB material.…”

mentioning

confidence: 93%

mentioning

confidence: 99%

See 3 more Smart Citations

Analysis of the intermediate-band absorption properties of type-II GaSb/GaAs quantum-dot photovoltaics

et al. 2017

View full text Add to dashboard Cite

show abstract

Intermediate band solar cells: Present and future

Ramiro

Martı́

2020

Progress in Photovoltaics

View full text Add to dashboard Cite

In the quest for high-efficiency photovoltaics (PV), the intermediate band solar cell (IBSC) was proposed in 1997 as an alternative to tandem solar cells. The IBSC offers 63% efficiency under maximum solar concentration using a single semiconductor material. This high-efficiency limit attracted the attention of the PV community, yielding to numerous intermediate band (IB) studies and IBSC prototypes employing a plethora of candidate IB materials. As a consequence, the principles of operation of the IBSC have been demonstrated, and the particularities and difficulties inherent to each different technological implementation of the IBSC have been reasonably identified and understood. From a theoretical and experimental point of view, the IBSC research has reached a mature stage. Yet we feel that, driven by the large number of explored materials and technologies so far, there is some confusion about what route the IBSC research should take to transition from the proof of concept to high efficiency. In this work, we give our view on which the next steps should be. For this, first, we briefly review the theoretical framework of the IBSC, the achieved experimental milestones, and the different technological approaches used, with special emphasis on those recently proposed.

show abstract

New Trends in Solar Cells Research

Gîrtan¹

2017

Future Solar Energy Devices

View full text Add to dashboard Cite

Three-Bandgap Absolute Quantum Efficiency in GaSb/GaAs Quantum Dot Intermediate Band Solar Cells

Cited by 22 publications

References 34 publications

Analysis of the intermediate-band absorption properties of type-II GaSb/GaAs quantum-dot photovoltaics

Analysis of the intermediate-band absorption properties of type-II GaSb/GaAs quantum-dot photovoltaics

Intermediate band solar cells: Present and future

New Trends in Solar Cells Research

Contact Info

Product

Resources

About