DLTFS INVESTIGATION OF InGaAsN/GaAs TANDEM SOLAR CELL
Arpád Kósa – Ľubica Stuchlíková – Wojciech Dawidowski – Juraj Jakuš – Beata Ściana – Damian Radziewicz – Damian Pucicki – Ladislav Harmatha – Jaroslav Kováč – Marek Tłaczala
In this paper authors present the results of identification of emission and capture processes in tandem solar cell structures based on quaternary InGaAsN semiconductor alloys by DLTFS (Deep Level Transient Fourier Spectroscopy) and by analytical evaluation processes. The energies of five trap levels ET1 = 0.77 eV, ET2 = 0.47 eV, ET3 = 0.64 eV, HT1 = 0.62 eV and HT2 = 0.53 eV were identified with reliable accuracy. These values were obtained by available analytical procedures, verified by simulations and confirmed by reference structures with basic layer types and compared with possible reference trap data. Native structural defects in GaAs were stated as the origin of these deep energy levels.
Keywords: tandem solar cell, deep level transient Fourier spectroscopy, deep energy levels