EUPVSEC, September 2015, Hamburg, Germany
5 oral presentations
- Nano-Imprint Textured Intermediate Reflectors for Advanced Light Management in Multi-Junction Solar Cells, JÜLICH
- Process development for heterojunction IBC cells on thin silicon foils bonded to glass, IMEC
- On the role of sodium in the morphology and device properties of inkjet-printed Cu2ZnSn(S,Se)4 absorbers, HZB
- Cheetah project introduction, Dissemination of WP8 project results, ECN
- Ultrathin wafer development and Cell processing, CEA-INES
- Potential for Cost Reduction of PV Technology - Impact of CHEETAH Research Innovations, SolarPower Europe
R&D on high efficiency concepts, efficiency developments
N-type front and rear contact cells, varying from lower cost bifacial approaches (eta ~21 %) towards higher cost, high efficiency and monofacial devices (ISE: 22.5 % (imec) 25 % (ISE, topCON))
ISE (S. Glunz) presented TOPCon technology which stands for tunnel oxide passivated contacts. With this concept they achieved a record efficiency of 25.1 %. The cells have a simple structure that is very similar to Al-BSF cells with a full area back contact and is therefore very cost-effective.
IBC (Interdigitated Back Contact) cells : > 21 up to 23.5 % achieved by ISFH for small area cells
P-PERC: efficiency typically above 20%
o Trina: 21.4% PERC solar cell large area screen printed
o ISFH: Bifacial PERC solar cell >21% with 80% bificiality
o 60 cells with 21.3% average efficiency
o 308 Wp module (60 cells), CtM 100.7%
Increasing R&D interest for hybrid tandem device structures with perovskite top cells (2- and 4 Terminal)
o Crystalline Silicon (HIT) + Perovskite: 4T 22.8% (EPFL)
o Crystalline Silicon (HIT) + Perovskite: 4T 28%!! (Kaneka)
Light trapping in general:
V. Depauw presented a very comprehensive study “When Nanophotonics Meet Thin Crystalline-Silicon Photovoltaics”. The presented results stem from the photoNvoltaics project and deal with the impact of front surface textures for ultra-thin c-Si absorbers on the conversion efficiency. This is done by integrating different nanotextures and additional simulations with genetic algorithms for pattern optimization.
Most PV industries nowadays are reluctant in adopting innovative and advanced X-Si concepts line Back Contact (MWT, IBC,…) because of high investment costs, high risks, no proven bankability and go for incremental improvement of existing concepts with minimal changes in equipment and process flows
The following announcements were made:
TRINA will startup pilot line IBC solar cells (and modules)
o Aim: efficiency 23% and increase to towards 24%
Meyer Burger: installation of SHJ production line in Hungary
Solar World: 1 GWp p-PERC in Arnstadt: 21% stabilized efficiency
Thin films (CIGS, CdTE, perovskites and OPV)
CIGS cells in combination with ZnS/ZnOS buffer layer and Alkali Post Deposition Treatment. Results in a record efficiency value of 21.7% cell efficiency (certified) (ZSW)
First Solar presented CdTe cell efficiencies of 21.5%, and champion module efficiencies of 18.6%. With Voc of 903 mV CdTe is also a potential candidate as top cell in hybrid tandems. EMPA is working on this.
Increasing interest for perovskite device R&D as top cells in tandem structures and in single junction cell and modules. After the efficiency hunt, more focus in the R&D will be given on stability, up scaling, cost and LCA
Efficiencies for OPV typically semi-transparent and low eff. < 5% (exception Heliatek)
Lifetimes in range of years
The interest in OPV in terms of public funding for R&D is decreasing or even disappearing.
There are OPV companies getting close to market (Heliatek, Mitsubishi Chemical, CSEM Brasil, Belectric) in applications where high efficiency and lifetimes are less important, but where other application criteria like design, colour flexibility give OPBV a unique advantage
The invited talk of EPFL (triple/quadrupol) presented the latest progresses and achievements (at EPFL as well as worldwide) in tandem triple and quadruple junction cells based on a-Si:H, a-SiGe:H and µc-Si:H. Applications of some of these device for water splitting were discussed.