Page 96 - ISES SWC50

S Robert Hastings
Country: Switzerland
Year Started Research: 1975
Title of Research: Solar Architecture
University: National Bureau of Standards in USA and EMPA , ETH and
AEU Ltd in Switzerland
Still Active in Research: No

In 1975, Robert made a career shift from conventional architecture to solar building research. At the US Center
for Building Technology, with a colleague he wrote a handbook: Window Design Strategies to Conserve Energy
(CBT Publication of the Year). His next project was leading “SUNCAT: Solar Use in Cities and Towns”. His team
of architects, economists and behavioural scientists explored urban planning ideas to capture sun on facades
and in arcaded streets. In 1980, on a travel grant, he worked at the Building Physics Dept. of the Swiss EMPA.
Meanwhile, the US halted federal solar research, so he gratefully accepted the Swiss offer to continue helping
coordinate research for a foundation, NEFF. Subsequently, Dr. G. Schriber of the Federal Office of Energy asked
him to represent Switzerland in a 4-year project: “Passive Solar Buildings” of the International Energy Agency
and to lead a Swiss research program of the same name.Wanting to also teach, he moved to the Swiss ETH and
offered a popular dipl. elective on solar buildings, as well as guest lecturing at 12 universities worldwide (Teacher
of the Year Award at the Danube Univ.). He led further IEA programs: “Solar Commercial & Institutional Buildings”,
“Solar Air Systems” and Solar “Sustainable Housing” (UK Energy Institute Award). While working with experts
from Europe, Asia and North America he co-authored ten books in German and English and gave 11 keynote talks
at international conferences. One colleague, P. Holzer, was instrumental in his becoming Professor and Head of the
Dept. of Buildings & Environment at the Danube University for two years. Finally, he founded Architecture, Energy
and Environment Ltd. (AEU) which consulted with architects. Together with two partner firms the AEU developed
a design for a solar neighbourhood of atria houses (1st prize in an EU design competition).

Rudolf Hezel
Country: Germany
Year Started Research: 1978
Title of Research: Photovoltaics
University: University University Erlangen-Nürnberg,
Leibniz-University Hannover, ISFH
Still Active in Research: No

In 1978, as a new era in photovoltaics, low-temperature surface passivation of silicon solar cells was introduced
by R. Hezel at the University Erlangen-Nürnberg. It is achieved by deposition of charged dielectric layers of silicon
nitride (SiNx) and aluminium oxide (Al2O3) below 500°C. Both films became key components of present and future
silicon solar cells. R. Hezel’s further R&D work consisted in basic and applied research including Auger and Electron
Energy Loss spectroscopy and electrical characterization of Si/insulator interfaces. Based on charged SiNx, the
novel MIS-inversion layer solar cell (MIS-IL), invented by R. Hezel, was transferred to an industrial pilot line (1992
Innovation award of the German Industry). In 1994 450kW MIS-IL solar cells were installed in Europe’s largest
PV plant in Toledo (Spanish-German project). In 1994 R. Hezel became Professor at the Physics department of
the Leibniz University Hannover and director of the Institute for Solar Energy Research (ISFH) at Hameln. From
1997 onward R. Hezel and co-workers developed fully nitride-passivated bifacial silicon solar cells, e.g. of the
back-collecting type (Back OECO, 21.5% and 18.1% efficiencies). In 2002 a high-throughput in-line machine for
large-scale plasma-deposition of SiNx films was developed at ISFH in cooperation with industrial partners. The
high-quality SiNx passivation and antireflection layers paved the way to the first industrial mass-production of
reliable solar cells, soon culminating in a world-wide boom of solar electricity. Back in 1985, as another highlight,
R. Hezel introduced an innovative rear-surface configuration for solar cells with gridded base contacts and AL2O3
as low-temperature passivation between the line-shaped contact fingers in order to substitute the conventional
high-temperature processed back-surface field (BSF). Decades later this novel structure, combined with SiNx,
became the basic element of the next-generation industrial solar cell (PERC) with strongly increased efficiency.

78 | ISES SWC50 - The Century of Solar-Stories and Visions