volume | PIER Journals

Abstract

A model of solar cell embedding quantum dots in the intrinsic layer of a p-i-n solar cell has been presented. With proper selection of material, size and fractional volume, quantum dots can provide an intermediate band between the valence and conduction bands of the matrix material, which will absorb photons with energy lower than the original bandgap to absorb more incident photons in the otherwise unused spectral irradiance. The design approach to acquire the highest efficiency of the conventional p-i-n solar cell is presented as a benchmark. Quantum dots are then embedded in the intrinsic region of the reference solar cell to improve its efficiency. InAs is chosen to implement the quantum dots, to be embedded in the p-i-n solar cell made of GaAs. With a more packed arrangement of QD's from that in the literatures, the simulation results shows that the efficiency of the conventional GaAs p-i-n solar cell can be increased by 1.05%.

1. Fonash, S. J., Solar Cell Device Physics, 2nd Ed., Academic Press, 2010.

2. Shockley, W. and H. J. Queisser, "Detailed balance limit of efficiency of pn junction solar cells," J. Appl. Phys., Vol. 3, No. 3, 510-519, 1961.
doi:10.1063/1.1736034

3. Landsberg, P. T. and P. Baruch, "The thermodynamics of the conversion of radiation energy for photovoltaics," J. Phys. A: Math., Vol. 22, 1911-1926, 1989.
doi:10.1088/0305-4470/22/11/028

4. Solankia, C. S. and G. Beaucarneb, "Advanced solar cell concepts," Energy Sustain. Develop., Vol. 11, No. 3, 17-23, 2007.
doi:10.1016/S0973-0826(08)60573-6

5. Kayes, B. M., et al. "27.6% conversion e±ciency, a new record for single-junction solar cells under 1 sun illumination," Photovolt. Special. Conf., 4-8, 2011.

6. Green, M. A., et al. "Solar cell efficiency tables (version 42)," Prog. Photovolt. Res. Appl., Vol. 21, No. 5, 827-837, 2013.

7. Green, M. A., "Third generation photovoltaics: Ultra-high conversion efficiency at low cost," Prog. Photovolt. Res. Appl., Vol. 9, 123-135, 2001.
doi:10.1002/pip.360

8. Newman, F., F., et al., "Optimization of inverted metamorphic multijunction solar cells for field-deployed concentrating PV systems," IEEE Photovolt. Special. Conf., 1611-1616, 2009.

9. Luque, A. and S. Hegedus, Handbook of Photovoltaic Science and Engineering, 93-107, John Wiley, 2003.
doi:10.1002/0470014008

10. Hu, W. G., T. Inoue, O. Kojima, and T. Kita, "Effects of absorption coe±cients and intermediate-band filling in InAs/GaAs quantum dot solar cells," Applied Phys. Lett., Vol. 97, 193106, 2010.
doi:10.1063/1.3516468

11. Luque, A., A. Marti, and C. Stanley, "Understanding intermediate-band solar cells," Nature Photon., Vol. 6, 146-152, 2012.
doi:10.1038/nphoton.2012.1

12. Nakata, Y., Y. Sugiyama, and M. Sugawara, Molecular Beam Epitaxy Growth of Self-assembled InAs/GaAs Quantum Dots, Ch. 2, Academic, 1990.

13. Bhattacharya, P., S. Ghosh, and A. D. Stiff-Roberts, "Quantum dot opto-electronic devices," Ann. Rev. Materials Res., Vol. 34, 1-40, 2004.
doi:10.1146/annurev.matsci.34.040203.111535

14. Cuadra, L., A. Marti, and A. Luque, "Present status of intermediate band solar cell research," Thin Solid Films., Vol. 451-452, 593-599, 2004.
doi:10.1016/j.tsf.2003.11.047

15. Raffaelle, R. P., et al. "Multi-junction solar cell spectral tuning with quantum dots," IEEE World Conf. Photovolt. Energy Conv., Vol. 1, 162-166, 2006.

16. Gorji, N. E., M. H. Zandic, M. Houshmandc, and M. Shokri, "Transition and recombination rates in intermediate band solar cells," Scientia Iranica, Vol. 19, No. 3, 806-811, 2012.
doi:10.1016/j.scient.2012.02.005

17. Lin, C. C., M. H. Tan, C. P. Tsai, K. Y. Chuang, and T. S. Lay, "Numerical study of quantum-dot-embedded solar cells," IEEE J. Select. Topics Quantum Electron., Vol. 19, No. 5, 1-10, 2013.

18. Marti, A., L. Cuadra, and A. Luque, "Quantum dot intermediate band solar cell," IEEE Photovolt. Special. Conf., 940-943, 2000.
doi:10.1109/PVSC.2000.916039

19. Lin, A. S., "Modeling of solar cell e±ciency improvement using optical gratings and intermediate absorption band,", Ph.D. Thesis, University of Michigan, 2010.

20. Marti, A., L. Cuadra, and A. Luque, "Design constraints of the quantum-dot intermediate band solar cell," Physica E, Vol. 14, No. 1-2, 150-157, 2002.
doi:10.1016/S1386-9477(02)00368-5

21. Pellegrini, G., G. Mattei, and P. Mazzoldi, "Finite depth square well model: Applicability and limitations," J. Appl. Phys., Vol. 97, No. 7, 193106, 2005.
doi:10.1063/1.1868875

22. Horiguchi, S., "Validity of effective mass theory for energy levels in Si quantum wires," Physica B, Vol. 227, No. 1-4, 336-338, 1996.
doi:10.1016/0921-4526(96)00435-8

23. Nanda, K. K., F. E. Kruis, and H. Fissan, "Energy levels in embedded semiconductor nanoparticles and nanowires," Nano Lett., Vol. 1, No. 11, 605-611, 2011.
doi:10.1021/nl0100318

24. Baskoutas, S. and A. F. Terzis, "Size-dependent band gap of colloidal quantum dots," J. Appl. Phys., Vol. 99, No. 1, 013708, 2006.
doi:10.1063/1.2158502

25. Kasap, S. and P. Capper, Handbook of Electronic and Photonic Materials, 54-327, Springer, 2006.

26. Holmstrom, P., L. Thylen, and A. Bratkovsky, "Dielectric function of quantum dots in the strong confnement regime," J. Appl. Phys., Vol. 107, No. 6, 064307, 2010.
doi:10.1063/1.3309343

27. Boyd, R., "Nonlinear Optics," Elsevier, 135-206, 2008.

28. Luque, A., A. Marti, N. Lopez, E. Antolin, E. Canovas, C. Stanley, C. Farmer, and P. Diaz, "Operation of the intermediate band solar cell under nonideal space charge region conditions and half filling of the intermediate band," J. Appl. Phys., Vol. 99, 094503, 2006.
doi:10.1063/1.2193063

29. Marti, A., L. Cuadra, and A. Luque, "Partial filling of a quantum dot intermediate band for solar cells," IEEE Trans. Electron. Dev., Vol. 48, No. 10, 2394-2399, 2002.
doi:10.1109/16.954482

30. alik, E. D., Handbook of Optical Constants of Solids, Academic Press, 1998.

Dr. Yi-Hsien Lin

Prof. Jean-Fu Kiang