intermediate band solar cells

Advanced Inorganic & novel Hybrid Materials

The research in intermediate band Solar cell (IBSC)  aims to exceeding the Shockley–Queisser limit [1] on the efficiency of a cell by  introducing  intermediate band (IB) energy level between the valence and conduction bands of the semiconductor-like material [2]. This increases the induced photocurrent and thereby efficiency

Prof. A.Luque and A.Martì   first derived a theoretical limit for an IB device with one midgap energy level using detailed balance [2] They assumed no carriers were collected at the IB and that the device was under full concentration [2] They found the maximum efficiency to be 63.2%, for a bandgap of 1.95eV with the IB 0.71eV from either the valence or conduction band. Under one sun illumination the limiting efficiency is 47%.[2]

Green and Brown expanded upon these results by deriving the theoretical efficiency limit for a device with infinite IBs.[22] By introducing more IB’s, even more of the incident spectrum can be utilized. After performing the detailed balance, they found the maximum efficiency to be 77.2%.[22]

IBs have theoretical potential to become high efficiency devices, but they are hard to make. 

Many approaches have been proposed for engineering this IB. We list next some of the strategies being followed to identify these materials and implement solar cells with them:

• Quantum dots [3],
• Insertion of impurities at high densities [4],
• Highly mismatched alloys [5],
• First principle calculations [6],
• Dye sensitized + TT annihilation [7]

 

References:

[1] W. Shockley and H. J. Queisser, "Detailed Balance Limit of Efficiency of p-n Junction Solar Cells," Journal of Applied Physics, vol. 32, pp. 510-519, 1961.
[2] A. Luque and A. Martí, "Increasing the efficiency of ideal solar cells by photon induced transitions at intermediate levels," Physical Review Letters, vol. 78, pp. 5014–5017, 1997.
[3]A. Martí, L. Cuadra, and A. Luque, "Quantum dot intermediate band solar cell," Conference Record of the Twenty-Eighth IEEE Photovoltaic Specialists Conference, 2000., pp. 940-943, 2000.
[4]A. Luque, A. Martí, E. Antolín, and C.Tablero, "Intermediate bands versus levels in non-radiative recombination," Physica B, vol. 382, pp. 320-327, 2006.
[5] K. M. Yu, W. Walukiewicz, J. Wu, W. Shan, J. W. Beeman, M. A. Scarpulla, et al., "Diluted II-VI Oxide Semiconductors with Multiple Band Gaps," Physical Review Letters, vol. 91, pp. 246403-4, 2003.
[6]  P. Palacios, I. Aguilera, K. Sanchez, J. C. Conesa, and P. Wahnon, "Transition-Metal-Substituted Indium Thiospinels as Novel Intermediate-Band Materials: Prediction and Understanding of Their Electronic Properties," Physical Review Letters, vol. 101, pp. 046403-4, 2008.
[7]C. Simpson, T. M. Clarke, R. W. MacQueen, Y. Y. Cheng, A. J. Trevitt, A. J. Mozer, et al., "An intermediate band dye-sensitised solar cell using triplet-triplet annihilation," Physical Chemistry Chemical Physics, vol. 17, pp. 24826-24830, 2015.
[8]A. Martí, E. Antolin, C. R. Stanley, C. D. Farmer, N. Lopez, P. Diaz, et al., "Production of Photocurrent due to Intermediate-to-Conduction-Band Transitions: A Demonstration of a Key Operating Principle of the Intermediate-Band Solar Cell," Physical Review Letters, vol. 97, pp. 247701-4, 2006.
[9]P. G. Linares, A. Martí, E. Antolín, C. D. Farmer, I. Ramiro, C. R. Stanley, et al., "Voltage recovery in intermediate band solar cells," Solar Energy Materials and Solar cells, vol. 98, pp. 240-244, 2012.
[10]Í. Ramiro, A. Martí, E. Antolín, and A. Luque, "Review of Experimental Results Related to the Operation of Intermediate Band Solar Cells," IEEE Journal of Photovoltaics, vol. 4, pp. 736-748, 2014.
[11]R. T. Ross and A. J. Nozik, "Efficiency of hot-carrier solar energy converters," Journal of Applied Physics, vol. 53, pp. 3813-3818, 1982.
[12]P. Wurfel, "Solar energy conversion with hot electrons from impact ionisation," Solar Energy Materials and Solar Cells, vol. 46, pp. 43-52, Apr 1997.
[13]G. J. Conibeer, J. F. Guillemoles, and M. A. Green, "Phononic Band Gap Engineering for Hot Carrier Solar Cell Absorbers," 20th European Photovoltaic Solar Energy Conference, pp. 35-38, 2005.
[14]J. A. R. Dimmock, S. Day, M. Kauer, K. Smith, and J. Heffernan, "Demonstration of a hot-carrier photovoltaic cell," Progress in Photovoltaics, vol. 22, pp. 151-160, Feb 2014.
[15] G. Conibeer, S. Shrestha, S. J. Huang, R. Patterson, H. Z. Xia, Y. Feng, et al., "Hot carrier solar cell absorber prerequisites and candidate material systems," Solar Energy Materials and Solar Cells, vol. 135, pp. 124-129, Apr 2015.
[16]Y. Yao and D. König, "Comparison of bulk material candidates for hot carrier absorber," Solar Energy Materials and Solar Cells, vol. 140, pp. 422-427, 9// 2015.
[17] R. Brendel, J. H. Werner, and H. J. Queisser, "Thermodynamic efficiency limits for semiconductor solar cells with carrier multiplication," Solar Energy Materials and Solar Cells, vol. 41-2, pp. 419-425, Jun 1996.
[18]S. Kolodinski, J. H. Werner, and H. J. Queisser, "Quantum efficiencies exceeding unity in silicon leading to novel selection principles for solar cell materials," Solar Energy Materials and Solar cells, vol. 33, pp. 275-285, 1994.
[19]A. J. Nozik, "Quantum dot solar cells " Physica E, vol. 14, pp. 115-120, 2002.
[20] O. E. Semonin, J. M. Luther, S. Choi, H.-Y. Chen, J. Gao, A. J. Nozik, et al., "Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell," Science, vol. 334, pp. 1530-1533, Dec 16 2011.
[21] A. Marti and A. Luque, "Electrochemical Potentials (Quasi-Fermi Levels) and the Operation of Hot-Carrier, Impact-Ionization, and Intermediate-Band Solar Cells," Photovoltaics, IEEE Journal of, vol. 3, pp. 1298-1304, 2013.
[22] Brown, Andrew S., and Martin A. Green. "Impurity Photovoltaic Effect: Fundamental Energy Conversion Efficiency Limits." Journal of Applied Physics 92.3 (2002): 1329. Web.