Details

Autor(en) / Beteiligte

• FIORE, A
• ROSSETTI, M
• ALLOING, B
• PARANTHOEN, C
• CHEN, J. X
• GEELHAAR, L
• RIECHERT, H

Titel

Carrier diffusion in low-dimensional semiconductors: A comparison of quantum wells, disordered quantum wells, and quantum dots

Ist Teil von

• Physical review. B, Condensed matter and materials physics, 2004-11, Vol.70 (20), p.205311.1-205311.12, Article 205311

Ort / Verlag

Ridge, NY: American Physical Society

Erscheinungsjahr

2004

Link zum Volltext

Quelle

American Physical Society [PROLA]

Beschreibungen/Notizen

• We present a comparative study of carrier diffusion in semiconductor heterostructures with different dimensionality [InGaAs quantum wells (QWs), InAs quantum dots (QDs), and disordered InGaNAs QWs (DQWs)]. In order to evaluate the diffusion length in the active region of device structures, we introduce a method based on the measurement of the current-voltage and light-current characteristics in light-emitting diodes where current is injected in an area <1 μm2. By analyzing the scaling behavior of devices with different sizes, we deduce the effective active area, and thus the diffusion length. A strong reduction in the diffusion length is observed going from QWs (Ld≈2.7 μm) to QDs (Ld<100 nm), DQWs being an intermediate case (Ldiff≈0–200 nm depending on the carrier density). These results show that lateral composition fluctuations, either intended or unintended, produce strong carrier localization and significantly affect the carrier profile in a device even at room temperature