Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 55: Photonic crystals

HL 55.7: Talk

Friday, March 31, 2006, 13:00–13:15, BEY 154

Realization of Electrically Active Photonic Crystal Nanocavities — •Simon Grimminger, Felix Hofbauer, Michael Kaniber, Susanne Dachs, Hubert J. Krenner, Gerhard Abstreiter, and Jonathan J. Finley — Walter Schottky Institute, TU München, 85748 Garching, Germany

We present investigations of electrically tunable InGaAs self-assembled quantum dots (QDs) embedded in 2D photonic crystal (PC) defect nanocavities. The samples consist of (Al)GaAs p-i-n diodes with a single layer of dots in the intrinsic region. Low mode volume (V<(λ/n)³), high-Q (∼2000) nanocavities are formed by etching a hexagonal lattice of air holes through the p-i-n junction and introducing defects to produce reduced symmetry H1-cavities. A 180nm thick freestanding membrane containing the p-i-n diode is then realized by selective wet etching and electrical contacts to the p and n-doped regions enable us to apply static electric field perturbations to QDs in the cavity.

Such active PC nanocavities were studied using spatially resolved luminescence and photocurrent absorption spectroscopy. The experiments show that the electric field is uniform over the 200 × 200 µ m diode structure. Furthermore, quenching of the PL is observed for fields >50kV/cm due to carrier tunneling escape from the dots that occurs faster than the radiative lifetime. By measuring the PL quenching as a function of position on the PC and nanocavity we electrically probe the local density of photonic states. Furthermore, the devices have the potential to study cavity-single QD coupling in an electrically tunable system.