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Quantum Dot Infrared Photodetectors: Photoresponse Enhancement Due to Potential Barriers

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ABSTRACT

Potential barriers around quantum dots (QDs) play a key role in kinetics of photoelectrons. These barriers are always created, when electrons from dopants outside QDs fill the dots. Potential barriers suppress the capture processes of photoelectrons and increase the photoresponse. To directly investigate the effect of potential barriers on photoelectron kinetics, we fabricated several QD structures with different positions of dopants and various levels of doping. The potential barriers as a function of doping and dopant positions have been determined using nextnano3 software. We experimentally investigated the photoresponse to IR radiation as a function of the radiation frequency and voltage bias. We also measured the dark current in these QD structures. Our investigations show that the photoresponse increases ~30 times as the height of potential barriers changes from 30 to 130 meV.

No MeSH data available.


Photocurrent density of the sample B45 at T = 80 K as a function of optical pumping from LED.
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Figure 6: Photocurrent density of the sample B45 at T = 80 K as a function of optical pumping from LED.

Mentions: Photocurrent densities for sample B45 at different power of LED's radiation are shown in Figure 6. A photocurrent response increases linearly with a background power and finally saturates at high power. The optical pumping allowed us to increase the photoresponse by three orders of magnitude. This effect is mainly due to an increase in the electron population in the quantum dot energy levels.


Quantum Dot Infrared Photodetectors: Photoresponse Enhancement Due to Potential Barriers
Photocurrent density of the sample B45 at T = 80 K as a function of optical pumping from LED.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211266&req=5

Figure 6: Photocurrent density of the sample B45 at T = 80 K as a function of optical pumping from LED.
Mentions: Photocurrent densities for sample B45 at different power of LED's radiation are shown in Figure 6. A photocurrent response increases linearly with a background power and finally saturates at high power. The optical pumping allowed us to increase the photoresponse by three orders of magnitude. This effect is mainly due to an increase in the electron population in the quantum dot energy levels.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Potential barriers around quantum dots (QDs) play a key role in kinetics of photoelectrons. These barriers are always created, when electrons from dopants outside QDs fill the dots. Potential barriers suppress the capture processes of photoelectrons and increase the photoresponse. To directly investigate the effect of potential barriers on photoelectron kinetics, we fabricated several QD structures with different positions of dopants and various levels of doping. The potential barriers as a function of doping and dopant positions have been determined using nextnano3 software. We experimentally investigated the photoresponse to IR radiation as a function of the radiation frequency and voltage bias. We also measured the dark current in these QD structures. Our investigations show that the photoresponse increases ~30 times as the height of potential barriers changes from 30 to 130 meV.

No MeSH data available.