Composition dependent growth dynamics in molecular beam epitaxy of GaInNAs solar cells
Tutkimustuotos › › vertaisarvioitu
|Julkaisu||Solar Energy Materials and Solar Cells|
|DOI - pysyväislinkit|
|Tila||Julkaistu - toukokuuta 2014|
We have investigated the role of the nitrogen content, the growth parameters, and the annealing processes involved in molecular beam epitaxy of GaInNAs solar cells lattice-matched to GaAs. The nitrogen composition was varied between 1% and 5%. The influence of the growth temperature was assessed by performing photoluminescence, atomic force microscopy, X-ray diffraction, reflection high-energy electron diffraction, quantum efficiency and light-biased current-voltage measurements. The growth temperature ensuring the best cell parameters was found to be 440 C. At this temperature we were able to incorporate up to 4% of nitrogen and achieve a good material quality. Further increase of the N composition to 5% led to phase separation. For the lattice matched samples grown within the optimal temperature range, we have identified a clear (1×3) surface reconstruction. Using the optimized growth we have demonstrated a GaInNAs p-i-n solar cell structure containing 4% nitrogen, that exhibited a short-circuit current density as high as 33.8 mA/cm2 in respect to effective area illuminated. These measurements have been performed under real sun AM1.5 (~1000 W/m2) illumination. © 2014 Elsevier B.V.