Dr Udo Romer

Dr Udo Romer

Research Associate
  • 2016: Dr.-Ing. (PhD) in electrical engineering from Gottfried Wilhelm Leibniz Universität Hannover in Germany
  • 2010: Dipl.-Phys. (Masters Degree in Physics) from Justus-Liebig-Universität Gießen
Engineering
Photovoltaic and Renewable Energy Engineering

I am a DECRA fellow in the School of Photovoltaics and Renewable Energy Engineering, working on multi-junction (MJ) solar cells for biomedical applications and high efficiency III-V MJ concentrator solar cells (see Research Activities).

 

I obtained my Diplom in Physics from the Justus-Liebig-Universität Gießen, Germany and worked towards my PhD at the Institute for Solar Energy Research Hameln (ISFH) in Hamelin, Germany, under supervision of Professor Niels Peter Harder, Professor Robby Peibst and Professor Tobias Wietler. My thesis research focussed on ion implanted, large area back-contact Si solar cells and on highly carrier selective poly-Si contacts for c-Si solar cells.

After receiving my PhD in electrical engineering from the Gottfried Wilhelm Leibniz Universität Hannover in Germany I moved to Sydney, Australia to work with Professor Alison Lennon at UNSW on inkjet and laser patterning processes for plated contacts for large area back-contacted Si solar cells and together with Professor Bram Hoex, on doped poly-Si passivating contacts. In 2018 I started my DFG (German Research Foundation) Research Fellowship at UNSW on inkjet printed doping of poly-Si contacts and in 2020 I joined the research Groups of A/Prof. Nicholas Ekins-Daukes and Dr. Stephen Bremner, where I worked on fabrication processes for III-V and III-V on Si solar cells.

Location
School of Photovoltaic and Renewable Energy Engineering, Tyree Energy Technologies Building (TETB) H6 Level1 Desk No - 123WS 8
  • Journal articles | 2024
    Deng S; Cai Y; Roemer U; Ma FJ; Rougieux F; Huang J; Cheng Y; Green MA; Song N, 2024, 'Mitigating parasitic absorption in Poly-Si contacts for TOPCon solar cells: A comprehensive review', Solar Energy Materials and Solar Cells, 267, http://dx.doi.org/10.1016/j.solmat.2024.112704
    Journal articles | 2024
    Katkus T; Ng SH; Mu H; Le NHA; Stonytė D; Khajehsaeidimahabadi Z; Seniutinas G; Baltrukonis J; Ulčinas O; Mikutis M; Sabonis V; Nishijima Y; Rienäcker M; Römer U; Krügener J; Peibst R; John S; Juodkazis S, 2024, 'Bessel-Beam Direct Write of the Etch Mask in a Nano-Film of Alumina for High-Efficiency Si Solar Cells', Advanced Engineering Materials, http://dx.doi.org/10.1002/adem.202400711
    Journal articles | 2023
    Pusch A; Römer U; Culcer D; Ekins-Daukes NJ, 2023, 'Energy Conversion Efficiency of the Bulk Photovoltaic Effect', PRX Energy, 2, http://dx.doi.org/10.1103/prxenergy.2.013006
    Journal articles | 2022
    Liu M; Römer U; Ekins-Daukes NJ; Lennon A, 2022, 'Optical analysis of light management for finger designs in CPV systems', Progress in Photovoltaics: Research and Applications, 30, pp. 1219 - 1227, http://dx.doi.org/10.1002/pip.3570
    Journal articles | 2022
    Röhr JA; Sartor BE; Duenow JN; Qin Z; Meng J; Lipton J; Maclean SA; Römer U; Nielsen MP; Zhao S; Kong J; Reese MO; Steiner MA; Ekins-Daukes NJ; Taylor AD, 2022, 'Identifying optimal photovoltaic technologies for underwater applications', iScience, 25, http://dx.doi.org/10.1016/j.isci.2022.104531
    Journal articles | 2022
    Sharma AS; Pusch A; Nielsen MP; Römer U; Tayebjee MJY; Rougieux FE; Ekins-Daukes NJ, 2022, 'Constraints imposed by the sparse solar photon flux on upconversion and hot carrier solar cells', Solar Energy, 237, pp. 44 - 51, http://dx.doi.org/10.1016/j.solener.2022.03.037
    Journal articles | 2022
    Tabernig SW; Soeriyadi AH; Römer U; Pusch A; Lamers D; Juhl MK; Payne DNR; Nielsen MP; Polman A; Ekins-Daukes NJ, 2022, 'Avoiding Shading Losses in Concentrator Photovoltaics Using a Soft-Imprinted Cloaking Geometry', IEEE Journal of Photovoltaics, 12, pp. 1116 - 1127, http://dx.doi.org/10.1109/JPHOTOV.2022.3182277
    Journal articles | 2021
    Lepkowski DL; Grassman TJ; Boyer JT; Chmielewski DJ; Yi C; Juhl MK; Soeriyadi AH; Western N; Mehrvarz H; Römer U; Ho-Baillie A; Kerestes C; Derkacs D; Whipple SG; Stavrides AP; Bremner SP; Ringel SA, 2021, '23.4% monolithic epitaxial GaAsP/Si tandem solar cells and quantification of losses from threading dislocations', Solar Energy Materials and Solar Cells, 230, http://dx.doi.org/10.1016/j.solmat.2021.111299
    Journal articles | 2020
    Ye Q; Western NJ; Romer U; Bremner SP, 2020, 'Characterizing Point Contacting by Localized Dielectric Breakdown and Its Use in Silicon Solar Cell Applications', IEEE Journal of Photovoltaics, 10, pp. 78 - 84, http://dx.doi.org/10.1109/JPHOTOV.2019.2953394
    Journal articles | 2018
    Hsiao PC; Song N; Wang X; Shen X; Phua B; Colwell J; Romer U; Johnston B; Lim S; Shengzhao Y; Verlinden P; Lennon A, 2018, '266-nm ps laser ablation for copper-plated p-type selective emitter perc silicon solar cells', IEEE Journal of Photovoltaics, 8, pp. 952 - 959, http://dx.doi.org/10.1109/JPHOTOV.2018.2834629
    Journal articles | 2018
    Song N; Romer U; Gentle A; Lim S; Li Z; Hsiao PC; Gong B; Zhang X; Verlinden P; Lennon A, 2018, 'Metallization method for interdigitated back-contact silicon solar cells employing an insulating resin layer and a Ti/Ag/Cu metal Stack', IEEE Journal of Photovoltaics, 8, pp. 916 - 922, http://dx.doi.org/10.1109/JPHOTOV.2018.2825465
    Journal articles | 2017
    Rienacker M; Bossmeyer M; Merkle A; Romer U; Haase F; Krugener J; Brendel R; Peibst R, 2017, 'Junction Resistivity of Carrier-Selective Polysilicon on Oxide Junctions and Its Impact on Solar Cell Performance', IEEE Journal of Photovoltaics, 7, pp. 11 - 18, http://dx.doi.org/10.1109/JPHOTOV.2016.2614123
    Journal articles | 2016
    Peibst R; Römer U; Larionova Y; Rienäcker M; Merkle A; Folchert N; Reiter S; Turcu M; Min B; Krügener J; Tetzlaff D; Bugiel E; Wietler T; Brendel R, 2016, 'Working principle of carrier selective poly-Si/c-Si junctions: Is tunnelling the whole story?', Solar Energy Materials and Solar Cells, 158, pp. 60 - 67, http://dx.doi.org/10.1016/j.solmat.2016.05.045
    Journal articles | 2016
    Rienäcker M; Merkle A; Römer U; Kohlenberg H; Krügener J; Brendel R; Peibst R, 2016, 'Recombination Behavior of Photolithography-free Back Junction Back Contact Solar Cells with Carrier-selective Polysilicon on Oxide Junctions for Both Polarities', Energy Procedia, 92, pp. 412 - 418, http://dx.doi.org/10.1016/j.egypro.2016.07.121
    Journal articles | 2015
    Römer U; Peibst R; Ohrdes T; Lim B; Krügener J; Wietler T; Brendel R, 2015, 'Ion implantation for poly-Si passivated back-junction back-contacted solar cells', IEEE Journal of Photovoltaics, 5, pp. 507 - 514, http://dx.doi.org/10.1109/JPHOTOV.2014.2382975
    Journal articles | 2014
    Peibst R; Römer U; Hofmann KR; Lim B; Wietler TF; Krügener J; Harder NP; Brendel R, 2014, 'A simple model describing the symmetric I-V characteristics of p polycrystalline Si/n monocrystalline Si, and n polycrystalline Si/p monocrystalline Si junctions', IEEE Journal of Photovoltaics, 4, pp. 841 - 850, http://dx.doi.org/10.1109/JPHOTOV.2014.2310740
    Journal articles | 2014
    Römer U; Peibst R; Ohrdes T; Lim B; Krügener J; Bugiel E; Wietler T; Brendel R, 2014, 'Recombination behavior and contact resistance of n+ and p+ poly-crystalline Si/mono-crystalline Si junctions', Solar Energy Materials and Solar Cells, 131, pp. 85 - 91, http://dx.doi.org/10.1016/j.solmat.2014.06.003
    Journal articles | 2014
    Schulte-Huxel H; Römer U; Blankemeyer S; Merkle A; Larionova Y; Steckenreiter V; Peibst R; Kajari-Schroeder S; Brendel R, 2014, 'Two-level metallization and module integration of point-contacted solar cells', Energy Procedia, 55, pp. 361 - 368, http://dx.doi.org/10.1016/j.egypro.2014.08.104
    Journal articles | 2013
    Haase F; Kajari-Schröder S; Römer U; Neubert T; Petermann JH; Peibst R; Harder NP; Brendel R, 2013, 'Increased front surface recombination by rear-side laser processing on thin silicon solar cells', IEEE Journal of Photovoltaics, 3, pp. 976 - 984, http://dx.doi.org/10.1109/JPHOTOV.2013.2261573
    Journal articles | 2012
    Haas G; Lautenschlaeger S; Roemer U; Eisermann S; Laufer A; Pinnisch M; Meyer BK, 2012, 'Growth of Cubic Zinc Sulfide on (001) GaP Substrates', E-MRS 2011 FALL SYMPOSIUM I: ADVANCES IN TRANSPARENT ELECTRONICS, FROM MATERIALS TO DEVICES III, 34, http://dx.doi.org/10.1088/1757-899X/34/1/012003
    Journal articles | 2010
    Lautenschlaeger S; Eisermann S; Hofmann MN; Roemer U; Pinnisch M; Laufer A; Meyer BK; Von Wenckstern H; Lajn A; Schmidt F; Grundmann M; Blaesing J; Krost A, 2010, 'Morphological, structural and electrical investigations on non-polar a-plane ZnO epilayers', Journal of Crystal Growth, 312, pp. 2078 - 2082, http://dx.doi.org/10.1016/j.jcrysgro.2010.04.029
  • Conference Papers | 2022
    Soeriyadi AH; Hollemann C; Madumelu C; Haase F; Römer U; Brendel R; Peibst R; Hallam BJ, 2022, 'Impact of Firing and Capping Layers on Long-term Stability of Doped Poly-Si Passivating Contact Layers', in AIP Conference Proceedings, http://dx.doi.org/10.1063/5.0089658
    Conference Papers | 2021
    Lepkowski DL; Kasher T; Boyer JT; Blumer ZH; Yi C; Juhl MK; Soeriyadi AH; Mehrvarz H; Romer U; Ho-Baillie A; Bremner SP; Ringel SA; Grassman TJ, 2021, 'Recent Advances in GaAsP/Si Top Cell Enabling 27% Tandem Efficiency', in Conference Record of the IEEE Photovoltaic Specialists Conference, pp. 1644 - 1646, http://dx.doi.org/10.1109/PVSC43889.2021.9518768
    Conference Papers | 2021
    Liu M; Romer U; Ekins-Daukes NJ; Lennon A, 2021, 'Optical Analysis of Secondary Optics for Solar Concentrators with a View to Optimising Cell Metallisation', in Conference Record of the IEEE Photovoltaic Specialists Conference, pp. 2270 - 2272, http://dx.doi.org/10.1109/PVSC43889.2021.9518911
    Conference Papers | 2020
    Liu M; Soeriyadi AH; Song N; Hsiao P-C; Romer U; Ekins-Daukes N; Lennon A, 2020, 'Formation Mechanism of Cu-based Ohmic Contacts for GaAs Solar Cells', in 2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC), IEEE, ELECTR NETWORK, pp. 829 - 832, presented at 47th IEEE Photovoltaic Specialists Conference (PVSC), ELECTR NETWORK, 15 June 2020 - 21 August 2020, https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000653077100205&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1
    Conference Papers | 2020
    Liu M; Soeriyadi AH; Song N; Hsiao PC; Romer U; Ekins-Daukes N; Lennon A, 2020, 'Formation Mechanism of Cu-based Ohmic Contacts for GaAs Solar Cells', in Conference Record of the IEEE Photovoltaic Specialists Conference, pp. 0829 - 0832, http://dx.doi.org/10.1109/PVSC45281.2020.9300525
    Conference Papers | 2019
    Wang H; Römer U; Lei X; Wei Y; Al Abed A; Ladouceur F; Silvestri L; Lovell N; Roemer U, 2019, 'Towards bi-directional electro-optic neuronal interfaces', in Goldys EM; Gibson BC (ed.), Proceedings of SPIE - The International Society for Optical Engineering. Biophotonics Australasia 2019, Society of Photo-optical Instrumentation Engineers, Melbourne, presented at ANZCOP 2019, Melbourne, 08 December 2019 - 12 December 2019, http://dx.doi.org/10.1117/12.2539997
    Conference Papers | 2018
    Hsiao PC; Zhang W; Li Z; Romer U; Lennon A; Zhang DW, 2018, 'Direct Copper Plating to IWO for Silicon Heterojunction Solar Cells', in 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion, WCPEC 2018 - A Joint Conference of 45th IEEE PVSC, 28th PVSEC and 34th EU PVSEC, Institute of Electrical and Electronics Engineers (IEEE), HI, Waikoloa, pp. 3719 - 3721, presented at 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC), HI, Waikoloa, 10 June 2018 - 15 June 2018, http://dx.doi.org/10.1109/PVSC.2018.8547698
    Conference Papers | 2017
    Rienacker M; Bossmeyer M; Merkle A; Romer U; Haase F; Krugener J; Brendel R; Peibst R, 2017, 'Notice of Removal: Junction resistivity of carrier selective polysilicon on oxide junctions and its impact on the solar cell performance', in 2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017, pp. 1 - 7, http://dx.doi.org/10.1109/PVSC.2017.8366491
    Conference Papers | 2017
    Römer U; Song N; Li Z; Li Y; Zhang X; Shengzhao Y; Verlinden PJ; Lennon A, 2017, 'Decoupling the metal layer of back contact solar cells - Optical and electrical benefits', in Energy Procedia, Freiburg, Germany, pp. 907 - 913, presented at 7th International Conference on Silicon Photovoltaics, SiliconPV 2017, Freiburg, Germany, 03 April 2017 - 05 April 2017, http://dx.doi.org/10.1016/j.egypro.2017.09.290
    Conference Papers | 2014
    Peibst R; Romer U; Larionova Y; Schulte-Huxel H; Ohrdes T; Haberle M; Lim B; Krugener J; Stichtenoth D; Wutherich T; Schollhorn C; Graff J; Brendel R, 2014, 'Building blocks for back-junction back-contacted cells and modules with ion-implanted poly-Si junctions', in Proceedings of the 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC), Denver, presented at 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC), Denver, 08 June 2014 - 13 June 2014, http://dx.doi.org/10.1109/PVSC.2014.6925049
    Conference Papers | 2014
    Romer U; Merkle A; Peibst R; Ohrdes T; Lim B; Krugener J; Brendel R, 2014, 'Ion-implanted Poly-Si / c-Si Junctions as a Back-surface Field in Back-Junction Back-Contacted Solar Cells', in Proceedings of the 28th European Photovoltaic Solar Energy Conference, 29th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, pp. 1107 - 1110, presented at 29th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 22 September 2014 - 26 September 2014, http://dx.doi.org/10.4229/EUPVSEC20142014-2AV.3.61
    Conference Papers | 2013
    Brendel R; Dullweber T; Gogolin R; Hannebauer H; Harder NP; Hensen J; Kajari-Schroder S; Peibst R; Petermann JH; Romer U; Schmidt J; Schulte-Huxel H; Steckenreiter V, 2013, 'Recent Progress and Options for Future Crystalline Silicon Solar Cells', in Proceedings of the 28th European Photovoltaic Solar Energy Conference, 28th European Photovoltaic Solar Energy Conference and Exhibition, Paris, presented at 28th European Photovoltaic Solar Energy Conference and Exhibition, Paris, 30 September 2013 - 04 October 2013, http://dx.doi.org/10.4229/28thEUPVSEC2013-2BP.1.1
    Conference Papers | 2013
    Romer U; Peibst R; Ohrdes T; Larionova Y; Harder NP; Brendel R; Grohe A; Stichtenoth D; Wutherich T; Schollhorn C; Krokoszinski HJ; Graff J, 2013, 'Counterdoping with patterned ion implantation', in Proceedings of the 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC), Tampa, presented at 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC), Tampa, 16 June 2013 - 21 June 2013, http://dx.doi.org/10.1109/PVSC.2013.6744375
    Conference Papers | 2012
    Ohrdes T; Romer U; Larionova Y; Peibst R; Altermatt PP; Harder NP, 2012, 'High Fill-Factors of Back-Junction Solar Cells without Front Surface Field Diffusion', in Proceedings of the 27th European Photovoltaic Solar Energy Conference, 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, pp. 866 - 869, presented at 27th European Photovoltaic Solar Energy Conference and Exhibition, Frankfurt, 24 September 2012 - 28 September 2012, http://dx.doi.org/10.4229/27thEUPVSEC2012-2DO.3.5
    Conference Posters | 2012
    Romer U, 2012, 'Limits for short-pulse laser processing of high efficiency crystalline silicon solar cells on thin wafers', Hangzhou, presented at 22nd International PV Science and Engineering Conference, Hangzhou, 05 September 2012 - 09 September 2012

  • 2023-2026 ARC Linkage Project on "Advanced metallisation for III-V Photovoltaic Solar Power Systems"
  • 2021-2024 ARC DECRA on "Nervous tissue stimulation using Multi-Junction Silicon Photodiodes"
  • 2019-2020 AUSIAPV Collaboration Grant on "Silicon Solar Cells with Silicon Carbide Passivated Contacts"
  • 2018-2019 DFG Research Stipend on "Doping of poly-Si contacts for high efficiency back junction back contact silicon solar cells using inkjet-printed doping sources"

  • Solar World Junior Einstein Award 2016 for my PhD thesis
  • Silicon PV Award 2014 for one of the ten best ranked contributions to the Silicon PV conference 2014

In my DECRA fellowship which started in mid 2021, I am aiming to fabricate multi-junction photodiode arrays for use in brain machine interfaces like retinal implants.

Background: Two of the main causes of vision loss, retinitis pigmentosa and age-related macular degeneration, are caused by a degeneration of photoreceptors in the retina, while the remaining visual pathway stays intact. By placing electrodes in the retina, it is possible to electrically stimulate the remaining intact neural tissue and restoring vision.

The School of Photovoltaic & Renewable Energy Engineering within the UNSW Faculty of Engineering has been at the leading edge of solar cell development for over 30 years, reporting many world record solar cell efficiencies. In a collaboration with the UNSW Graduate School of Biomedical Engineering we are now aiming to develop solar cells that can stimulate nervous tissue upon illumination and to fabricate arrays of small solar cells as prototypes for wireless retinal prostheses and other light powered brain machine interfaces.