1 BP Statistical Review of World Energy 2016 (BP, 2016); https://www.bp.com/content/dam/bp/pdf/energy-economics/statistical-review-2016/bp-statistical-review-of-world-energy-2016-full-report.pdf

2 World Energy Outlook 2015 (IEA, 2015); http://www.worldenergyoutlook.org/weo2015

3 Solar Quarterly Market Update—China, United States and Japan to Lead Global Solar Installation in 2016 (Mercom Capital Group, 2016); http://www.solareb2b.it/wp-content/uploads/2016/04/ForecastReports-MercomSolarQuarterlyMarketUpdateApr2016.pdf

4 2014 Outlook: Let the Second Gold Rush Begin (Deutsche Bank, 2014); https://www.deutschebank.nl/nl/docs/Solar_-_2014_Outlook_Let_the_Second_Gold_Rush_Begin.pdf

5 Technology Roadmap for Photovoltaic (ITRPV): 2015 Results Including Maturity Report (VDMA Photovoltaic Equipment, 2016); http://www.itrpv.net/Reports/Downloads

6 Battaglia, C., Cuevasb, A. & Wolf, S. D. High efficiency crystalline silicon solar cells: status and perspectives. Energy Environ. Sci. 9, 1552–1576 (2016).

7 Best Research-Cell Efficiencies (NREL, 2016); http://www.nrel.gov/pv/assets/images/efficiency-chart.png

8 Green, M. A., Emery, K., Hishikawa, Y., Warta, W. & Dunlop, E. D. Solar cell efficiency tables (version 48). Prog. Photovolt. Res. Appl. 24, 905–913 (2016).

9 Taguchi, M. et al. HIT cells: high efficiency crystalline Si cells with novel structure. Prog. Photovolt. 8, 492–502 (2000).

10 Lammert, M. D. & Schwartz, R. J. The interdigitated back contact solar cell: a silicon solar cell for use inconcentrated sunlight. IEEE Trans. Electron Devices 24, 337–341 (1977).

11 Swanson, R. M. et al. Point-contact silicon solar cells. IEEE Trans. Electron Devices 31, 661–664 (2005).

12 Masuko, K. et al. Achievement of more than 25% conversion efficiency with crystalline silicon heterojunction solar cell. IEEE J. Photovolt. 4, 1433–1435 (2014).

13 Smith, D. D. et al. Silicon solar cells with total area efficiency above 25%. In 2016 IEEE 43rd Photovoltaic Spec. Conf. 3351–3355 (IEEE, 2016).

14 Adachi, D., Hernandez, J. L. & Yamamoto, K. Impact of carrier recombination on fill factor for large area heterojunction crystalline Si solar cell with 25.1% efficiency. Appl. Phys. Lett. 107, 233506 (2015).

15 Green, M. A., Emery, K., Hishikawa, Y., Warta, D. & Dunlop, E. D. Solar cell efficiency tables (version 39). Prog. Photovolt. Res. Appl. 20, 12–20 (2012).

16 Kerr, M. J., Cuevas, A. & Campbel, P. Limiting efficiency of crystalline silicon solar cells due to Coulomb-enhanced Auger recombination. Prog. Photovolt. Res. Appl. 11, 97–104 (2003).

17 Richter, A., Hermle, M. & Glunz, S. W. Reassessment of the limiting efficiency for crystalline silicon solar cells. IEEE J. Photovolt. 3, 1184–1191 (2013).

18 Taguchi, M. et al. 24.7% record efficiency HIT solar cell on thin silicon wafer. IEEE J. Photovolt. 4, 96–99 (2014).

19 Hernandez, J. L. et al. High efficiency silver-free heterojunction silicon solar cell. Jpn. J. Appl. Phys. 51, 10NB04 (2012).

20 Hernandez, J. L. High efficiency copper electroplated heterojunction solar cells. In Proc. 27th EUPVSEC 655–656 (WIP, 2012).

21 Hernandez, J. L. et al. High efficiency copper electroplated heterojunction solar cells and modules—The path towards 25% cell efficiency. In Proc. 28th EUPVSEC 741–743 (WIP, 2014).

22 Wolf, S. D., Descoeudres, A., Holman, Z. C. & Ballif, C. High efficiency silicon heterojunction solar cells: a review. Green 2, 7–24 (2012).

23 Franklin, E. et al. Design, fabrication and characterisation of a 24.4% efficient interdigitated back contact solar cell. Prog. Photovolt. Res. Appl. 24, 411–427 (2014).

24 Dingemans, G. & Kessels, W. M. M. Status and prospects of Al2O3-based surface passivation schemes for silicon solar cells. J. Vac. Sci. Technol. A 30, 040802 (2012).

25 Green, M. A. The Passivated Emitter and Rear Cell (PERC): from conception to mass production. Sol. Energy Mater. Sol. Cells 143, 190 (2015).

26 Green, M. A. The path to 25% silicon solar cell efficiency: history of silicon cell evolution. Prog. Photovolt. Res. Appl. 17, 183–189 (2009).

27 Zhang, S. et al. 335 watt world record p-type mono-crystalline module with 20.6% efficient PERC solar cells. IEEE J. Photovolt. 6, 145–152 (2016).

28 Richter, A. et al. Silicon solar cells with full-area passivated rear contacts: influence of wafer resistivity on device performance on a 25% efficiency level. In 26th PVSEC (2016); http://pvsec-26.com/dr-armin-richter

29 Harrisona, S. et al. Back contact heterojunction solar cells patterned by laser ablation. Energy Procedia 92, 730–737 (2016).

30 Desrues, T., De Vecchi, S., D’Alonzo, G., Muñoz, D. & Ribeyron, P.-J. Influence of the emitter coverage on interdigitated back contact (IBC) silicon hetero-junction (SHJ) solar cells. In Proc. 40th IEEE Photovoltaic Spec. Conf. 857–886 (IEEE, 2014).

31 Lee, S. Y. et al. Analysis of a-Si:H/TCO contact resistance for the Si heterojunction back-contact solar cell. Sol. Energy Mater. Sol. Cells 120, 412–416 (2014).

32 Tomasi, A. et al. Backcontacted silicon heterojunction solar cells with efficiency > 21%. IEEE J. Photovolt. 4, 1046–1054 (2014).

33 Mingirulli, N. et al. Efficient interdigitated back-contacted silicon heterojunction solar cells. Phys. Status Solidi 5, 159–161 (2011).

34 Nakamura, J. et al. Development of heterojunction back contact Si solar cells. IEEE J. Photovolt. 4, 1491–1495 (2014).

35 Salomon, B. P. et al. Back-contacted silicon heterojunction solar cells: optical-loss analysis and mitigation. IEEE J. Photovolt. 5, 1293–1303 (2015).

36 Aberle, A. G. Surface passivation of crystalline silicon solar cells: a review. Prog. Photovolt. 8, 473–487 (2000).

37 Wang, E. Y., Yu, F. T. S., Sims, V. L., Brandhorst, E. W. & Broder, J. D. Optimum design of anti-reflection coating for silicon solar cells. In 10th IEEE Photovoltaic Spec. Conf. 168–171 (IEEE, 1973).

38 Fields, J. D. et al. The formation mechanism for printed silver-contacts for silicon solar cells. Nat. Commun. 7, 11143 (2016).

39 Zhang, X., Wan, Y., Bullock, J., Allen, T. & Cuevas, A. Low resistance Ohmic contact to p-type crystalline silicon via nitrogen-doped copper oxide films. Appl. Phys. Lett. 109, 052102 (2016).

40 Frühaufa, F., Sayadb, Y. & Breitensteina, O. Description of the local series resistance of real solar cells by separate horizontal and vertical components. Sol. Energy Mater. Sol. Cells 154, 23–34 (2016).

41 Sinton, R. A. & Cuevas, A. A quasi-steady-state open-circuit voltage method for solar cell characterization. In 16th Eur. Photovoltaic Solar Energy Conf. 1152–1155 (WIP-Renewable Energies, 2000).

42 Richter, A., Glunz, S. W., Werner, F., Schmidt, J. & Cuevas, A. Improved quantitative description of Auger recombination in crystalline silicon. Phys. Rev. B 86, 165202 (2012).

43 Cuevas, A. & Macdonald, D. Measuring and interpreting the lifetime of silicon wafers. Sol. Energy 76, 255–262 (2004).

44 Glunz, S. W., Nekarda, J., Mackel, H. & Cuevas, A. Analyzing back contacts of silicon solar cells by Suns-Voc-measurements at high illumination densities. In 22nd Eur. Photovoltaic Solar Energy Conf. 849–853 (WIP-Renewable Energies, 2007).

45 Chavali, R. V. K. et al. A generalized theory explains the anomalous Suns–Voc response of Si heterojunction solar cells. IEEE J. Photovolt. 7, 169–176 (2016).