Modelling and simulations

Light in a solar cell

  • we want to trap as much as possible light in the solar cell structures (but only that part of the spectrum which has higher energy than the energy band-gap of the semiconductor used)
  • we want to absorb as much as possible light in the active parts/layers of solar cell structure (absorption of light in supporting inactive parts of the structures, such as in contact layers only leads to heating of the cell)
  • absorbed light in active parts/layers of solar cell generates photo-current of the cell (active part of the cell present narrow region around the pn junction or the intrinsic layer (such as i-uc-Si:H in the figure nearby) in case of p-i-n structures of thin-film solar cells)


Aim of optical modelling and simulations

  • to analyze and improve above mentioned optical circumstances in solar cells and photovoltaic modules
  • to invent novel optical concepts based on simulation results supported by experiments


Motivation and meaning

  • the trends of solar cells production are going in the direction of thinning the structures
  • in solar cells with thin active layers light management and light trapping issues become very important
  • especially in thin-film solar cells there still exists a high potential to improve light trapping in the structures – optimization of the existing concepts and development of novel solutions are important!
  • implementation of simulation results and findings into lab solar cells and in photovoltaic modules in production

Research activities of LPVO


  • one-dimensional semi-coherent optical simulator SunShine (developed in LPVO, model description)
  • two-dimensional optical simulator FEMOS (developed in LPVO, model description)
  • the use of three-dimensional simulator MEEP (developed at MIT, USA, link)
  • development and use of novel optical models and simulators (e.g. to study plasmonic effects in solar cell structures with metal nano-particles, developed in co-operation of LPVO with HZB Germany,model description)
  • development of advanced combined optical models (e.g. geometrical optics + coherent model




Research of advanced optical concepts

Selected topics (published in journals):


Contact persons

Janez Krc

Benjamin Lipovsek



Services in the area of optical modelling and simulations