High-Efficiency Energy Up-Conversion by an "Auger Fountain" at an InP-AIInas Type-II Heterojunction

Seidel, W.; Titkov, A. N.; Jp, André; Voisin, P.; Voos, M.

doi:10.1103/physrevlett.73.2356

Cited by 119 publications

(83 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A direct consequence of that energy gain is upconverted photoluminescence (UPL). Such kinds of UPL have been observed in the PL of semiconductor heterojunctions [108,109,110]. These effects have been attributed to hot carriers, which are created in the optically excited QW or heterojunction by Auger recombination and ejected in the surrounding, nonabsorbing material where they recombine with native electrons or holes.…”

Section: Photoluminescence Up-conversionmentioning

confidence: 97%

Optical Properties of Si Nanocrystals

Ковалев¹,

Heckler²,

Polisski³

et al. 1999

phys. stat. sol. (b)

455

321

View full text Add to dashboard Cite

Section: Photoluminescence Up-conversionmentioning

confidence: 97%

Optical Properties of Si Nanocrystals

Ковалев¹,

Heckler²,

Polisski³

et al. 1999

phys. stat. sol. (b)

455

321

View full text Add to dashboard Cite

“…In semiconductor heterostructures and quantum dots, Auger recombination is the transfer of energy and momentum, released by the recombination of an electronhole pair to a third particle, that is, an electron (or hole), giving rise to an energetic electron (or hole). [22] Direct Auger recombination in inorganic semiconductors is obtained under the high carrier concentration regime provided by high doping or by high current-density injection. [23] It was previously described in organic semiconductors as one of the possible schemes of bimolecular recombination.…”

mentioning

confidence: 99%

Rubrene/Fullerene Heterostructures with a Half‐Gap Electroluminescence Threshold and Large Photovoltage

2007

View full text Add to dashboard Cite

Tremendous interest in organic semiconductors for the development of light-weight and flexible electronic devices has been generated, owing to their ease of fabrication and suitability to large-area applications. [1][2][3][4][5] However, there are still many unexplored possibilities offered by these conjugated materials. [6,7] We demonstrate here a new structure that permits efficient integration of both light-and current-generation functions from a rubrene/fullerene heterostructure into an efficient organic dual device (ODD). [8][9][10] The device behaves like a compound semiconductor device: The electroluminescence (EL) turn-on voltage is < 1 V with the characteristic color of rubrene. The solar power conversion efficiency reaches 3 % with a 5.3 mA cm -2 short-circuit current density and almost 1 V open-circuit voltage under AM 1.5 illumination. Surprisingly, the EL turn-on voltage is about half the value of the rubrene bandgap (2.2 eV), a fact that cannot be explained using current models of charge injection into organic semiconductors. A physical interpretation is proposed in terms of the so-called Auger fountain mechanism, [11] which we could implement into our molecular heterojunction. During the EL process in heterojunction devices, holes and electrons are injected into the hole and electron conducting layers, respectively. They then recombine near the interface to raise a photon that has a color characteristic of the recombination region. Whereas, for the photovoltaic (PV) effect in organic materials, electron-hole pairs created by a broadband light source form excitons that dissociate at the donor-acceptor (D-A) junction. It then generates a net bipolar current flow across the device. Interest in organic-based solar cells (OSCs) has grown because of experience and understanding gained from organic light-emitting diode (OLED) developments. The general understanding treats light and current generation as competing phenomena. Indeed, the working principle of organic solar cells is that photoluminescence (PL) is quenched by ultrafast charge transfer from the donor to the acceptor.[4] However, we have successfully integrated both efficient light-and current-generating functions in a discrete ODD device. 5,6,11,12-Tetraphenylnaphthacene, commonly known as rubrene, is used as a hole-transporting material, while fullerene (C 60 ) is used as an electron-transporting material. Both rubrene and fullerene are widely studied semiconductors, with among the highest field-effect mobility for holes and electrons, respectively. [12,13] Moreover, rubrene is also currently used as a yellow dopant for achieving OLEDs with white-light emission suitable for display and lighting applications, and fullerene is omnipresent as an acceptor in efficient OSCs. [14,15] We have made heterojunction devices that combine 35 nm thick rubrene and 25 nm thick C 60 layers sandwiched between transparent indium tin oxide (ITO) and 60 nm thick metal electrodes. A 40 nm thick layer of poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDO...

show abstract

“…Surprisingly however, this places the EL turn-on voltage at about half of the rubrene band gap (2.2 eV). The physical interpretation can be found into the so-called Auger mechanism 3 that we could implement in our molecular heterojunction diode. 5,6,11,12-tetraphenylnaphthacene, commonly known as rubrene (Aldrich, sublimed grade, see insert in Fig.…”

mentioning

confidence: 99%

“…In semiconductor heterostructures and quantum dots, Auger recombination is the transfer of energy and momentum released by the recombination of an electron-hole pair to a third particle, ie. an electron (or hole), giving rise to an energetic electron (or hole) 3 . Auger recombination in inorganic semiconductors is obtained under the high carrier concentration regime provided by high doping or by high current density injection 15 .…”

mentioning

confidence: 99%

Upconversion injection in rubrene/perylene-diimide-heterostructure electroluminescent diodes

Pandey

Nunzi

2007

Applied Physics Letters

View full text Add to dashboard Cite

We implement and demonstrate in this paper a scheme that permits to drive electroluminescence with an extremely low turn-on voltage. The device behaves like compound semiconductors, in which the electroluminescence turn-on voltage is about the same as the open circuit voltage for the photovoltaic effect. However, the electroluminescence turn-on voltage is about half of the band gap of the emitting material, that cannot be explained using current models of charge injection in organic semiconductors. We hereby propose explanation through an Auger-type two-step injection mechanism.2 Apart from their ease of fabrication and suitability to large area applications, there are many unexplored fields related to the peculiar physics of conjugated materials 1 . Of particular interest in that context is the recent discovery of the exceptionally low-threshold injection characteristics of rubrene crystals 2 . We implement here a resonant scheme that permits to drive electroluminescence (EL) with an extremely low turn-on voltage. The heterostructure device behaves like compound semiconductors, in which the EL turn-on voltage is about the same as the open circuit voltage for the photovoltaic effect. Surprisingly however, this places the EL turn-on voltage at about half of the rubrene band gap (2.2 eV). The physical interpretation can be found into the so-called Auger mechanism 3 that we could implement in our molecular heterojunction diode. 5,6,11,12-tetraphenylnaphthacene, commonly known as rubrene (Aldrich, sublimed grade, see insert in Fig. 1a), was used as a hole-transporting material, while N,N'-ditridecylperylene-3, 4, 9, 10-tetracarboxylic diimide (PTCDI, Aldrich, purum grade) was used as an electron transporting material. Both rubrene and PTCDI are widely studied semiconductors with among the highest fieldeffect mobility for holes 4 and electrons 5 , respectively. Moreover, rubrene is also currently used as a yellow dopant for achieving efficient light emitting diodes (LED) 6 and efficient photovoltaic (PV) not find explanation using current models of charge injection in organic semiconductors 8 , as we discuss in the following. Under 1V bias, electron-hole pairs with ~1eV electrochemical potential recombining at the rubrene/C 60 interface must create ~2eV excitons in rubrene to yield effective electroluminescence with the characteristic color of rubrene (Fig.2a). To understand better that halfgap EL phenomenon, it is necessary to figure the energetic steps involved, starting from charge injection at the organic-metal interface. Figure 3a figure 3a, that is not the case as figure 1 shows; Second, the energy barrier for thermal emission from PTCDI-LUMO to rubrene-LUMO is F i ≈ 1eV and the thermal emission current density can be estimated from the Richardson-Dushman equation:J th = AT 2 .exp(-F i /kT), where the theoretical value of A is 123 A.cm -2 K -2 . One obtains J th ≈ 50 pA/cm 2 , very far from the J ≈ 1 mA/cm 2 measured at V = 1V (Figure 1b). EL at a relatively lower 5 voltage than the semiconductor band-gap has b...

show abstract

High-Efficiency Energy Up-Conversion by an "Auger Fountain" at an InP-AIInas Type-II Heterojunction

Cited by 119 publications

References 7 publications

Optical Properties of Si Nanocrystals

Optical Properties of Si Nanocrystals

Rubrene/Fullerene Heterostructures with a Half‐Gap Electroluminescence Threshold and Large Photovoltage

Upconversion injection in rubrene/perylene-diimide-heterostructure electroluminescent diodes

Contact Info

Product

Resources

About