One of the most interesting discoveries originated from this project is the fabrication of NWs using a novel protocol that allows the growth of supported NWs avoiding electron beam lithography in its fabrication in any way (direct or indirect). In that work I have put the emphasis on the role of the seed nanoparticles that determine the quality of the NWs. This protocol controls the main parameters of the NWs such as their diameter, length, etc. Besides, the efficiency of the solar cells made using this method demonstrated the special relevance of the study of the electrical issues in NW solar cells. This has to be addressed by the correct passivation of the surface of the NWs.
Another important contribution of my work to the field of NW solar cells is the identification of the mechanisms that allow the growth of NWs with high aspect ratio and good homogeneity using metal organic chemical vapour deposition. In that work, I demonstrated the influence of the dopant concentration in order to increase the homogeneity of the NW array. Besides, I showed that this fabrication method for solar cells can be extended to other systems that can benefit from these results. In addition, I successfully developed a novel protocol to make NWs on cheap substrates avoiding the epitaxial growth. This preliminary work has proven to be important for the cost reduction of the fabrication of NWs devices.
Up to date, the published results derived from this project have been disseminated in the following peer-reviewed articles, meetings and conferences:
L. Francaviglia et al, 2018, 10.1021/acs.na006Eolett.7b05402
A. Dorodnyy et al, 2018, 10.1109/JSTQE.2018.2840339
- P. Romero-Gomez. LMPV Symposium June 2016. Light trapping in semitransparent organic solar cells. FOM institute Amolf, Amsterdam.
- D. Mikulik, P. Romero-Gomez, M. Ricci, G. Tutuncuoglu, F. Matteini, J. Vukajlovic, N. Vulic, M. Friedl, E. Alarcon-Llado, B. Dwir, A. Rudra, E. Kapon and A. Fontcuberta i Morral “From single NW solar cell to large scale NW array solar cell development through Conductive AFM analysis”, MRS spring, Phoenix, USA, 2017.
- D. Mikulik, M. Ricci, P. Romero-Gomez, G. Tutuncuoglu, F. Matteini, J. Vukajlovic, E. Alarcon-Llado and A. Fontcuberta i Morral “Single nanowire current‐voltage measurements by C-AFM and its effect on the output characteristics of solar cells based on nanowire ensembles” EMC17, South Bend, USA, 2017.
- A. Rudra, D. Mikulik, P. Romero Gomez, B. Dwir, A. Fontcuberta i Morral, E. Kapon “High temperature selective area metalorganic vapour phase epitaxy of GaAs nanowires using N2 as carrier gas” ORAL, EW-MOVPE17, France, 2017.
- P. Romero Gomez, D. Mikulik, G. Tutuncuoglu, H. Potts, M. Friedl, A. Fontcuberta i Morral “Large Scale Nanowire Solar Cells” Poster, Congrès Photovoltaïque National, Lausanne, Switzerland, 2017.
- P. Romero Gomez, D. Mikulik, G. Tutuncuoglu, H. Potts, M. Friedl, J. Vukajlovik-Plestina, B. Dwir, A. Rudra, E. Kapon, A. Fontcuberta i Morral “Robust nanowire arrays for new generation solar cells” Nanowire Week, Lund Sweden, 2017.
- D. Mikulik, M. Mintairov, V. Evstropov, P. Romero-Gomez, M. Shvarts, A. Fontcuberta I Morral “Intrinsic device properties of nanowire based solar cells using intensity-dependent measurements up to 1000 suns” ICPS, Montpellier, France, 2018.
- D Mikulik, Andrew C. Meng, Riad Berrazouane, P. Romero-Gomez, K. Tang, A. Fontcuberta i Morral, P. C. Mcintyre “Electrochemical Impedance Spectroscopy method to analyse interface states in semiconductor-oxide high-aspect-ratio structures” ICPS, Montpellier, France, 2018.