Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: hot carriers

Sortuj według:

Ogranicz wyniki do:

Hot carrier photocurrent induced by 0.92 eV photon energy radiation in a Si solar cell

Zharchenko Ihor, Gradauskas Jonas, Masalskyi Oleksandr, Rodin Aleksej

Opto-Electronics Review

2024

Vol. 32, No. 2

art. no. e150181

Absorption of the below-bandgap solar radiation and direct pre-thermalizational impact of a hot carrier (HC) on the operation of a single-junction solar cell are ignored by the Shockley-Queisser theory. The detrimental effect of the HC is generally accepted only via the thermalization-caused heating of the lattice. Here, the authors demonstrate experimental evidence of the HC photocurrent induced by the below-bandgap 0.92 eV photon energy radiation in an industrial silicon solar cell. The carriers are heated both through direct free-carrier absorption and by residual photon energy remaining after the electron-hole pair generation. The polarity of the HC photocurrent opposes that of the conventional generation photocurrent, indicating that the total current across the p-n junction is contingent upon the interplay between these two currents. A model of current-voltage characteristics analysis allowing us to obtain a reasonable value of the HC temperature was also proposed. This work is remarkable in two ways: first, it contributes to an understanding of HC phenomena in photovoltaic devices, and second, it prompts discussion of the HC photocurrent as a new intrinsic loss mechanism in solar cells.

Photovoltage formation across Si p-n junction exposed to laser radiation

Ašmontas S., Gradauskas J., Sužiedėlis A., Šilėnas A., Širmulis E., Švedas V., Vaičikauskas V., Vaičiūnas V., Žalys O., Kostylyov V.

Materials Science Poland

2018

Vol. 36, No. 2

337--340

Photovoltage formation across Si p-n junction exposed to laser radiation is experimentally investigated. Illumination of the junction with 1.06 μm wavelength laser radiation leads to formation of classical photovoltage Uph due to intense electronhole pair generation. When the photon energy is lower than the semiconductor forbidden energy gap, the photovoltage U is found to consist of two components, U = Uf + Uph. The first Uf is a fast one having polarity of thermoelectromotive force of hot carriers. The second Uph is classical photovoltage with polarity opposite to Uf. It is found that Uf is linearly dependent on laser intensity. The classical photovoltage is established to decrease with the rise of radiation wavelength due to decrease in two-photon absorption coefficient with wavelength. Predominance of each separate component in the formation of the net photovoltage depends on both laser wavelength and intensity.

Microwave-enhanced exciton delocalisation in low-dimensional CdTe/CdMnTe and CdMnTe/CdMgTe quantum well structures

Godlewski M., Ivanov V. Yu., Khachapuridze A.

Bulletin of the Polish Academy of Sciences. Chemistry

2000

Vol. 48, No. 4

346-354

In this work we descrjbe new application of the technique of optically detected cyclotron resonance (ODCR) to the studies of localisation processes in quantum well structures of CdTe/CdMnTe and CdMnTe/CdMgrre. Interaction between rnicrowave-eated free carriers, at cyclotron. resonance conditions, and either site- or impurity-localised excitons results in modificatjon of photoluminescence from the sample. In consequence, cyclotron resonance of free carriers can be detected optically. We show here that the tech-nique of ODCR allows us to monitor processes of carrier/exciton localisation and also to evaluate their influence on radiative recombination processes in quantum well structures. We conclude that localisation effects are crucial to explain operation of CdTe/CdMnTe and CdMnTe/CdMgTe structures as light modulators.