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Quantitative experimental assessment of hot carrier-enhanced solar cells at room temperature


In common photovoltaic devices, the part of the incident energy above the absorption threshold quickly ends up as heat, which limits their maximum achievable efficiency to far below the thermodynamic limit for solar energy conversion. Conversely, the conversion of the excess kinetic energy of the photogenerated carriers into additional free energy would be sufficient to approach the thermodynamic limit. This is the principle of hot carrier devices. Unfortunately, such device operation in conditions relevant for utilization has never been evidenced. Here, we show that the quantitative thermodynamic study of the hot carrier population, with luminance measurements, allows us to discuss the hot carrier contribution to the solar cell performance. We demonstrate that the voltage and current can be enhanced in a semiconductor heterostructure due to the presence of the hot carrier population in a single InGaAsP quantum well at room temperature. These experimental results substantiate the potential of increasing photovoltaic performances in the hot carrier regime.

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Fig. 1: Description of the hot carrier heterojunction device.
Fig. 2: Electrical characteristics of the heterojunction device.
Fig. 3: EQE and absorption model.
Fig. 4: Variation of carrier thermodynamic properties with laser intensity.
Fig. 5: Variation of carrier thermodynamic properties with bias voltage.
Fig. 6: Assessment of the hot carriers’ contribution to power generation.


  1. 1.

    Green, M. A. et al. Solar cell efficiency tables (version 50). Prog. Photovolt. Res. Appl. 25, 668–676 (2017).

    Article  Google Scholar 

  2. 2.

    Green, M. A. Third Generation Photovoltaics (Springer-Verlag, Berlin/Heidelberg, 2006).

  3. 3.

    Shockley, W. & Queisser, H. J. Detailed balance limit of efficiency of p-n junction solar cells. J. Appl. Phys. 32, 510–519 (1961).

    Article  Google Scholar 

  4. 4.

    Ross, R. T. & Nozik, A. J. Efficiency of hot-carrier solar energy converters. J. Appl. Phys. 53, 3813–3818 (1982).

    Article  Google Scholar 

  5. 5.

    Kettemann, S. & Guillemoles, J.-F. Thermoelectric field effects in low-dimensional structure solar cells. Phys. E Low Dimens. Syst. Nanostruct. 14, 101–106 (2002).

    Article  Google Scholar 

  6. 6.

    Würfel, P. Solar energy conversion with hot electrons from impact ionisation. Sol. Energy Mater. Sol. Cells 46, 43–52 (1997).

    Article  Google Scholar 

  7. 7.

    Rosenwaks, Y. et al. Hot-carrier cooling in GaAs: Quantum wells versus bulk. Phys. Rev. B 48, 14675–14678 (1993).

    Article  Google Scholar 

  8. 8.

    Xu, Z. Y. & Tang, C. L. Picosecond relaxation of hot carriers in highly photoexcited bulk GaAs and GaAs-AlGaAs multiple quantum wells. Appl. Phys. Lett. 44, 692–694 (1984).

    Article  Google Scholar 

  9. 9.

    Ryan, J. F. Time-resolved photoluminescence of two-dimensional hot carriers in GaAs-AlGaAs heterostructures. Phys. Rev. Lett. 53, 1841–1844 (1984).

    Article  Google Scholar 

  10. 10.

    Shah, J. Energy-loss rates for hot electrons and holes in GaAs quantum wells. Phys. Rev. Lett. 54, 2045–2048 (1985).

    Article  Google Scholar 

  11. 11.

    Leo, K. Reduced dimensionality of hot-carrier relaxation in GaAs quantum wells. Phys. Rev. B 37, 7121–7124 (1988).

    Article  Google Scholar 

  12. 12.

    Lugli, P. Nonequilibrium longitudinal-optical phonon effects in GaAs-AlGaAs quantum wells. Phys. Rev. Lett. 59, 716–719 (1987).

    Article  Google Scholar 

  13. 13.

    Conibeer, G. et al. Modelling of hot carrier solar cell absorbers. Sol. Energy Mater. Sol. Cells 94, 1516–1521 (2010).

    Article  Google Scholar 

  14. 14.

    Le Bris, A. & Guillemoles, J.-F. Hot carrier solar cells: Achievable efficiency accounting for heat losses in the absorber and through contacts. Appl. Phys. Lett. 97, 113506 (2010).

    Article  Google Scholar 

  15. 15.

    Le Bris, A. et al. Thermalisation rate study of GaSb-based heterostructures by continuous wave photoluminescence and their potential as hot carrier solar cell absorbers. Energy Environ. Sci. 5, 6225–6232 (2012).

    Article  Google Scholar 

  16. 16.

    Le Bris, A. et al. Hot carrier solar cells: controlling thermalization in ultrathin devices. IEEE J. Photovolt. 2, 506–511 (2012).

    Article  Google Scholar 

  17. 17.

    Hirst, L. C., Walters, R. J., Führer, M. F. & Ekins-Daukes, N. J. Experimental demonstration of hot-carrier photo-current in an InGaAs quantum well solar cell. Appl. Phys. Lett. 104, 231115 (2014).

    Article  Google Scholar 

  18. 18.

    Rodière, J., Lombez, L., Le Corre, A., Durand, O. & Guillemoles, J.-F. Experimental evidence of hot carriers solar cell operation in multi-quantum wells heterostructures. Appl. Phys. Lett. 106, 183901 (2015).

    Article  Google Scholar 

  19. 19.

    Esmaielpour, H. et al. Suppression of phonon-mediated hot carrier relaxation in type-II InAs/AlAs x Sb1 -x quantum wells: a practical route to hot carrier solar cells. Prog. Photovolt. Res. Appl. 24, 591–599 (2016).

    Article  Google Scholar 

  20. 20.

    Zhang, Y. et al. Extended hot carrier lifetimes observed in bulk In0.265±0.02Ga0.735N under high-density photoexcitation. Appl. Phys. Lett. 108, 131904 (2016).

    Article  Google Scholar 

  21. 21.

    Tedeschi, D. et al. Long-lived hot carriers in III–V nanowires. Nano Lett. 16, 3085–3093 (2016).

    Article  Google Scholar 

  22. 22.

    Gibelli, F., Lombez, L. & Guillemoles, J.-F. Accurate radiation temperature and chemical potential from quantitative photoluminescence analysis of hot carrier populations. J. Phys. Condens. Matter 29, 06LT02 (2017).

    Article  Google Scholar 

  23. 23.

    Esmaielpour, H. et al. Effect of occupation of the excited states and phonon broadening on the determination of the hot carrier temperature from continuous wave photoluminescence in InGaAsP quantum well absorbers. Prog. Photovolt. Res. Appl. 25, 782–790 (2017).

    Article  Google Scholar 

  24. 24.

    Dimmock, J. A. R., Day, S., Kauer, M., Smith, K. & Heffernan, J. Demonstration of a hot-carrier photovoltaic cell. Prog. Photovolt. Res. Appl. 22, 151–160 (2014).

    Article  Google Scholar 

  25. 25.

    Dimmock, J. A. R. et al. Optoelectronic characterization of carrier extraction in a hot carrier photovoltaic cell structure. J. Opt. 18, 074003 (2016).

    Article  Google Scholar 

  26. 26.

    Julian, A., Jehl, Z., Miyashita, N., Okada, Y. & Guillemoles, J. F. Insights on energy selective contacts for thermal energy harvesting using double resonant tunneling contacts and numerical modeling. Superlattices Microstruct. 100, 749–756 (2016).

    Article  Google Scholar 

  27. 27.

    Hanna, M. C., Zhenghao, L. & Nozik, A. J. Hot carrier solar cells. AIP Conf. Proc. 404, 309 (1997).

    Article  Google Scholar 

  28. 28.

    Rau, U. Superposition and reciprocity in the electroluminescence and photoluminescence of solar cells. IEEE J. Photovolt. 2, 169–172 (2012).

    Article  Google Scholar 

  29. 29.

    Lasher, G. & Stern, F. Spontaneous and stimulated recombination radiation in semiconductors. Phys. Rev. 133, A553–A563 (1964).

    Article  Google Scholar 

  30. 30.

    Gibelli, F., Lombez, L. & Guillemoles, J.-F. Two carrier temperatures non-equilibrium generalized Planck law for semiconductors. Phys. B Condens. Matter 498, 7–14 (2016).

    Article  Google Scholar 

  31. 31.

    Feng, Y. et al. Non-ideal energy selective contacts and their effect on the performance of a hot carrier solar cell with an indium nitride absorber. Appl. Phys. Lett. 100, 053502 (2012).

    Article  Google Scholar 

  32. 32.

    Würfel, P. The chemical potential of radiation. J. Phys. C Solid State Phys. 15, 3967–3985 (1982).

    Article  Google Scholar 

  33. 33.

    Tsui, E., Nelson, J., Barnham, K., Button, C. & Roberts, J. S. Determination of the quasi-Fermi-level separation in single-quantum-well p-i-n diodes. J. Appl. Phys. 80, 4599–4603 (1996).

    Article  Google Scholar 

  34. 34.

    Kluftinger, B., Barnham, K., Nelson, J., Foxon, T. & Cheng, T. Temperature-dependent study of the radiative losses in double-quantum well solar cells. Sol. Energy Mater. Sol. Cells 66, 501–509 (2001).

    Article  Google Scholar 

  35. 35.

    Nelson, J., Paxman, M., Barnham, K. W. J., Roberts, J. S. & Button, C. Steady-state carrier escape from single quantum wells. IEEE J. Quantum Electron. 29, 1460–1468 (1993).

    Article  Google Scholar 

  36. 36.

    Chemla, D., Miller, D., Smith, P., Gossard, A. & Wiegmann, W. Room temperature excitonic nonlinear absorption and refraction in GaAs/AlGaAs multiple quantum well structures. IEEE J. Quantum Electron. 20, 265–275 (1984).

  37. 37.

    Colocci, M., Gurioli, M. & Vinattieri, A. Thermal ionization of excitons in GaAs/AlGaAs quantum well structures. J. Appl. Phys. 68, 2809–2812 (1990).

  38. 38.

    Zitter, R. N. Saturated optical absorption through band filling in semiconductors. Appl. Phys. Lett. 14, 73–74 (1969).

    Article  Google Scholar 

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This work was carried out in the framework of a project of the IPVF (Institut Photovoltaïque d’Île-de-France). This project has been supported by the French Government in the framework of the programme of investment for the future (Programme d’Investissement d’Avenir) ANR-IEED-002-0. The authors acknowledge J. Even for the energy band structure simulation, T. Batté and N. Chevalier for technical assistance on sample and device fabrication, and P. Schultz and J. Connolly for carefully reading the manuscript.

Author contributions

J.-F.G. and L.L. planned the study; D.-T.N. acquired the data; D.-T.N., L.L. and F.G. contributed to data treatment; S.B.-R., A.L.-C. and O.D. designed and fabricated the samples; D.-T.N., L.L. and J.-F.G. contributed to data analysis and modelling and wrote the paper.

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Correspondence to Laurent Lombez.

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The authors declare no competing interests.

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Supplementary Information

Supplementary Notes 1–9, Supplementary Figures 1–11, Supplementary Table 1 and Supplementary References.

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Nguyen, DT., Lombez, L., Gibelli, F. et al. Quantitative experimental assessment of hot carrier-enhanced solar cells at room temperature. Nat Energy 3, 236–242 (2018).

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