Synopsys leverages TCAD for solar cells
The company purports that solar applications for its TCAD technology include cell analysis and optimization, ARC optimization, back contact cell design and exploration of novel structures and materials.
By Ann Steffora Mutschler, Senior Editor -- EDN, September 2, 2008
While EDA giant Synopsys Inc hasn’t formally announced its solar cell simulation technology, the company discussed the capabilities of its Sentaurus technology as applied to solar cell design during the Semicon West tradeshow held in July.
Synopsys acquired the Sentaurus technology with its acquisition of Avant! in 2001. Technology Modeling Associates (TMA), which was acquired by Avant! in the early 90s, developed the technology originally. Interestingly, many of TMA’s senior executives, which joined Avant! following the acquisition, are now in senior management at Magma Design Automation, which recently announced that it is developing its own solar cell design technology.
Already being used by a dozen+ customers along with a number of evaluations, according to Ric Borges, Synopsys senior product marketing manager, the technology is also being using for research purposes by a number of research institutes including Golden, Colorado-based National Renewable Energy Lab; Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany; The University of New South Wales in Australia; and the Hahn-Meitner Institute in Berlin, Germany.
Borges pointed out that Synopsys is aiming the TCAD Sentaurus technology on both silicon-based solar cells including crystalline silicon (c-Si), multi-crystalline silicon (mc-Si) and amorphous silicon (a-Si) along with compound semiconductors (single and multi-junction: GaAs, InGaP; CdTe; and CIGS: Cu(In,Ga)Se2).
On a general level, Synopsys believes the value of TCAD in solar cell design is that it gives key insights into the physics of cell operation, allows designers to optimize the efficiency of a solar cell and allows virtual exploration of new cell designs. As such, the Sentaurus simulation environment integrates all TCAD products inside a single environment; allows the editing of input files and parameterization; allows start/stop simulations, starts visualization, and summarizes results; schedules tasks on many CPUs; and allows for optimization of designs.
The process simulation features of Sentaurus are applicable to silicon-based solar cells, as it leverages the large body of work in CMOS technology. Specific process steps that can use the technology are diffusion, oxidation, implantation, deposition/etching and implementation of models for custom solar cell processes, Borges explained.
When used for optical simulation, models for optical generation can be created, interference effects for anti-reflection coatings can be examined and the tool can sweep through wavelength to obtain spectral generation G(λ,y) (image at left).
For device simulation (image at right), Synopsys said the tool can perform as a 1D / 2D / 3D simulator for DC / transient / AC analysis / optical AC / and noise analysis; for arbitrary materials; and has hetero structure capabilities. Also, Sentaurus can handle mixed-mode: numerical and compact SPICE models along with physics aspects including state-of-the-art transport models, quantum effects, physical model interface and high-efficiency linear solvers
In one example of a 2D cell optimization (image below), the Sentaurus tool allows the user to select parameters to be investigated, parameterize the TCAD model, run simulations and visualize the influence of each parameter.
In the end, Borges said there are many application areas for the tool including cell analysis and optimization (for efficiency); ARC optimization; back contact cell design; and exploration of novel structures and materials.
