Skip to main content
SpringerLink
Log in

Reduction in Photocurrent Loss and Improvement in Performance of Single Junction Solar Cell Due to Multistep Grading of Hydrogenated Amorphous Silicon Germanium Active Layer

  • Original Paper
  • Published:
Silicon Aims and scope Submit manuscript

Abstract

Single junction solar cells were fabricated with intrinsic hydrogenated amorphous silicon germanium (a-SiGe:H) as the active layer, that shows a 10% photovoltaic conversion efficiency. The a-SiGe:H active layer of the solar cells of type-A had constant band gap materials while that of type-B had a four step graded band gap by composition gradient (CG). The cells with composition gradient show an enhancement in fill factor and open circuit voltage (V oc) by 5% and 20 mV respectively, with respect to a cell without the graded band gap active layer. Such an enhanced device performance is attributed to reduction in recombination loss of photo-generated electron hole pairs. The effect of this photo-current loss was investigated in the electrical bias dependent external quantum efficiencies (EQE), illumination dependent current-voltage measurements and dark current-voltage characteristics. The device parameters like reverse saturation current density (J o), series resistance (R s) and diode quality factor (n) were also estimated. In comparison to the cell without the composition gradient, the EQE shows a reduced recombination loss across the whole wavelength range for the cell with the CG. Furthermore, the introduction of the CG results in a significantly increased shunt resistance from 720 to 1200 Ω.cm 2. The estimated n values of the cells under dark operating condition, decreases from 1.8 to 1.7 along with J o from 3 × 10 −7 down to 4.5 × 10 −8 A/cm 2 with CG, while the same parameters decreased from 3.73 to 3.06, 2.96 × 10 −6 to 3.05 × 10 −7 A/cm 2 respectively under AM1.5G insolation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Yan B, Yue G, Sivec L, Yang J, Guha S, Jiang C-S (2011) Innovative dual function nc-SiOx:H layer leading to a > 16% efficient multi-junction thin-film silicon solar cell. Appl Phys Lett 99:113512

    Article  Google Scholar 

  2. Cho J, Pham D P, Jung J, Shin C, Park J, Kim S, Tuan Le A H, Park H, Iftiquar S M, Yi J (2016) Improvement of hydrogenated amorphous silicon germanium thin film solar cells by different p-type contact layer. Mater Sci Semicond Process 41:480–484

    Article  CAS  Google Scholar 

  3. Cho J, Iftiquar S M, Kim M, Park J, Jung J, Kim J, Yi J (2016) Hydrogenated amorphous silicon germanium active layer for top cell of a multi junction cell structure. J Nanosci Nanotechnol 16:4870–4874

    Article  CAS  Google Scholar 

  4. Palinginis K C, Cohen J D, Yang J C, Guha S (2000) Defect bands in a-Si–Ge:H alloys with low Ge content. J Non-Crystal Solids 266–269(Part 2):665–669

    Article  Google Scholar 

  5. Zimmer J, Stiebig H, Wagner H (1998) a-SiGe:H based solar cells with graded absorption layer. J Appl Phys 84:611–617

    Article  CAS  Google Scholar 

  6. Jin-Won C, Jun Woong P, Yu Jin L, Seh-Won A, Heon-Min L, Park OO (2012) Graded layer modification for high efficiency hydrogenated amorphous silicon–germanium solar cells. Japan J Appl Phys 51:10NB16

    Article  Google Scholar 

  7. Schüttauf J-W, Niesen B, Löfgren L, Bonnet-Eymard M, Stuckelberger, M, Hänni S, Boccard M, Bugnon G, Despeisse M, Haug F-J, Meillaud F, Ballif C (2015) Amorphous silicon–germanium for triple and quadruple junction thin-film silicon based solar cells. Solar Energy Mater Solar Cells 133:163–169

    Article  Google Scholar 

  8. Lundszien D, Finger F, Wagner H (2002) A-Si:H buffer in a-SiGe:H solar cells. Solar Energy Mater Solar Cells 74:365–372

    Article  CAS  Google Scholar 

  9. Lundszien D, Yong F, Finger F (2002) The influence of the optical band gap of buffer layers at the p/i- and i/n-side on the performance of amorphous silicon germanium solar cells. In: Photovoltaic specialists conference, 2002. Conference record of the twenty-ninth. IEEE, pp 1218–1221

  10. Krajangsang T, Inthisang S, Dousse A, Moollakorn A, Hongsingthong, A, Kittisontirak S, Chinnavornrungsee P, Limmanee, A, Sritharathikhun J, Sriprapha K (2016) Band gap profiles of intrinsic amorphous silicon germanium films and their application to amorphous silicon germanium heterojunction solar cells. Opt Mater 51:245–249

    Article  CAS  Google Scholar 

  11. Liu B, Bai L, Zhang X, Wei C, Huang Q, Sun J, Ren H, Hou G, Zhao Y (2015) Fill factor improvement in PIN type hydrogenated amorphous silicon germanium thin film solar cells: omnipotent N type μc-SiOx:H layer. Solar Energy Mater Solar Cells 140:450–456

    Article  CAS  Google Scholar 

  12. Biron R, Pahud C, Haug F-J, Ballif C (2012) Origin of the V oc enhancement with a p-doped nc-SiOx:H window layer in n-i-p solar cells. J Non-Crystal Solids 358:1958–1961

    Article  CAS  Google Scholar 

  13. Park H, Iftiquar SM, Kim HW, Lee J, Le AHT, Yi J (2013) Diffused transmission and texture-induced defect with transparent conducting oxide front electrode of amorphous silicon solar cell. Semicond Sci Technol 28:115012

    Article  Google Scholar 

  14. Stangl R, Haschke J, Leendertz C (2009) Numerical simulation of solar cells and solar cell characterization methods: the open-source on demand program Afors-het, Version 2.4 Rugescu R D (ed), Solarenergy, Intech, Croatia

  15. Hegedus S S, Shafarman W N (2004) Thin-film solar cells: device measurements and analysis. Progress Photovolt Res Appl 12:155–176

    Article  CAS  Google Scholar 

  16. Hegedus S S (1997) Current–voltage analysis of a-Si and a-SiGe solar cells including voltage-dependent photocurrent collection. Progress Photovolt Res Appl 5:151–168

    Article  CAS  Google Scholar 

  17. Deng J, Wronski CR (2005) Carrier recombination and differential diode quality factors in the dark forward bias current-voltage characteristics of a-Si:H solar cells. J Appl Phys 98:024509

    Article  Google Scholar 

  18. Deng J, Pearce J M, Koval R J, Vlahos V, Collins R W, Wronski C R (2003) Absence of carrier recombination associated with the defect pool model in intrinsic amorphous silicon layers. Evidence from current–voltage characteristics on p–i–n and n–i–p solar cells. Appl Phys Lett 82:3023–3025

    Article  CAS  Google Scholar 

  19. Fang J, Chen Z, Hou G, Wang F, Chen X, Wei C, Wang G, Sun J, Zhang D, Zhao Y, Zhang X (2015) High-quality hydrogenated intrinsic amorphous silicon oxide layers treated by H 2 plasma used as the p/i buffer layers in hydrogenated amorphous silicon solar cells. Solar Energy Mater Solar Cells 136:172–176

    Article  CAS  Google Scholar 

  20. Guha S, Yang J, Pawlikiewicz A, Glatfelter T, Ross R, Ovshinsky, S R (1989) Band-gap profiling for improving the efficiency of amorphous silicon alloy solar cells. Appl Phys Lett 54:2330– 2332

    Article  CAS  Google Scholar 

  21. Jimenez Zambrano R, Rubinelli F A, Rath J K, Schropp R E I (2002) Improvement in the spectral responseat long wavelength of a-SiGe:H solar cells by exponential band gap design of the i-layer. J Non-Crystal Solids 299–302(Part 2):1131–1135

    Article  Google Scholar 

  22. Moon SY, You D J, Lee S E, Lee H (2013) In-situ monitoring and control of hydrogenated amorphous silicon–germanium band-gap profiling during plasma deposition process. Curr Appl Phys 13:1502–1505

    Article  Google Scholar 

  23. Zambrano RJ, Rubinelli F A, Arnoldbik W M, Rath J K, Schropp R E I (2004) Computer-aided band gap engineering and experimental verification of amorphous silicon–germanium solar cells. Solar Energy Mater Solar Cells 81:73–86

    Article  CAS  Google Scholar 

  24. Tang Z, Wang W, Wang D, Liu D, Liu Q, Yin M, He D (2010) The effect of Ar flow rate in the growth of SiGe:H thin films by PECVD. Appl Surf Sci 256:7032–7036

    Article  CAS  Google Scholar 

  25. Pieters BE, Zeman M, van Swaaij R A C M M, Metselaar W J (2004) Optimization of a-SiGe:H solar cells with graded intrinsic layers using integrated optical and electrical modeling. Thin Solid Films 451–452:294–297

  26. Abu-Ras D, Kirchartz T, Rau U (2011) Advanced characterization techniques for thin film solar cells. Wiley-VCH, Germany

    Book  Google Scholar 

  27. Banerjee A, Xu X, Yang J, Guha S (1995) Carrier collection losses in amorphous silicon and amorphous silicon–germanium alloy solar cells. Appl Phys Lett 67:2975–2977

    Article  CAS  Google Scholar 

  28. Chung Y-B, Lee D-K, Lim J-S, Hwang N-M (2011) Reduction of amorphous incubation layer by HCl addition during deposition of microcrystalline silicon by hot-wire chemical vapor deposition. Solar Energy Mater Solar Cells 95:211–214

    Article  CAS  Google Scholar 

  29. Iftiquar SM, Yi J (2016) Low reverse saturation current density of amorphous silicon solar cell due to reduced thickness of active layer. J Electr Eng Technol 11:939–942

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. College of Information and Communication Engineering, Sungkyunkwan University, Suwon, 440-746, Republic of Korea

    Duy Phong Pham, Jinjoo Park, Anh Huy Tuan Le, S. M. Iftiquar & Junsin Yi

  2. Department of Energy Science, Sungkyunkwan University, Suwon, 440-746, Republic of Korea

    Sangho Kim, Jaehyun Cho & Junhee Jung

Authors
  1. Duy Phong Pham
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sangho Kim
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jinjoo Park
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Anh Huy Tuan Le
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Jaehyun Cho
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Junhee Jung
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. S. M. Iftiquar
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Junsin Yi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to S. M. Iftiquar or Junsin Yi.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Pham, D.P., Kim, S., Park, J. et al. Reduction in Photocurrent Loss and Improvement in Performance of Single Junction Solar Cell Due to Multistep Grading of Hydrogenated Amorphous Silicon Germanium Active Layer. Silicon 10, 759–767 (2018). https://doi.org/10.1007/s12633-016-9527-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12633-016-9527-4

Keywords

Search

Navigation