Cuprous oxide-copper photovoltaic cells formed by high-temperature reduction

Berezin, Alexander A.; Weichmasn, F. L.

doi:10.1002/pssa.2210710132

Cited by 5 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2, curve a) at low intensities. This value is comparable to that obtained by Berezin and Weichman [27] for above band gap illumination. In thicker samples (as in Fig.…”

Section: Pulsed Excitationsupporting

confidence: 90%

Study of Anomalous Excitonic Transport in Cu₂O

Benson

Fortin

Mysyrowicz

1995

Physica Status Solidi (b)

View full text Add to dashboard Cite

An experimental study of excitonic transport in Cu,O is presented. Excitons are detected several mm away from their initial location, via the photovoltaic effect. Results at low exciton densities are well explained by a diffusive motion. However, at high densities, anomalous transport, in the form of excitonic packets propagating at constant speed, is observed. Threshold conditions for the onset of ballistic packet motion are determined as a function of lattice temperature and exciton densities. They are consistent with requirements for Bose-Einstein condensation of excitons. Double pulse experiments reveal an important attraction of low density probe particles towards a packet. The packet is suggested to correspond to the superfluid component of a quantum degenerate ecxitonic fluid.Une etude experimentale du transport d'excitons dans Cu,O a basse temperature est decrite. La migration d'excitons sur des distances de plusieurs mm est observee par effet photovolta'ique. A faibles densites, les particules obtissent a une loi de diffusion classique. Par contre, i haute densite, le nuage excitonique se propage a vitesse constante sous la forme d'un paquet ballistique. Les conditions d'appdrition du paquet ballistique sont en bond accord avec celles requises pour une condensation de Bose-Einstein d'excitons. Des experiences de type pompe-sonde indiquent que les particules sondes ajouttes en prksence d'un paquet sont entrainees par celui-ci. Nous attribuons le paquet a la composante superfluide du gaz excitonique.

show abstract

“…2, curve a) at low intensities. This value is comparable to that obtained by Berezin and Weichman [27] for above band gap illumination. In thicker samples (as in Fig.…”

Section: Pulsed Excitationsupporting

confidence: 90%

Study of Anomalous Excitonic Transport in Cu₂O

Benson

Fortin

Mysyrowicz

1995

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…The height of the Schottky barrier is not exactly known. In[39] an energetic distance of the valence band in Cu 2 O of 3.2 eV to the Fermi level in Cu is assumed, while in[40] a value of the Schottky barrier of ð0:7 AE 0:05Þ eV has been given, but no good rectifying properties of Cu or Au on Cu 2 O have been found in[41]. Additionally it can happen that an intermediate layer forms under the metal (here possibly some Cu x O with x 6 ¼ 2) and creates with the semiconductor the Schottky barrier while the contact between this layer and the metal has no influence[42].…”

mentioning

confidence: 99%

Some Considerations Concerning the Detection of Excitons by Field Ionization in a Schottky Barrier

Klingshirn

Fleck

Jörger

2002

phys. stat. sol. (b)

View full text Add to dashboard Cite

Dedicated to Professor Dr. Roland Zimmermann on the occasion of his 60th birthdayThe possibility of Bose-Einstein condensation of excitons in semiconductors and/or their superfluid transport are long-standing, still controversially discussed problems. In a recent series of experiments by E. Fortin and coworkers [1-3] [phys. stat. sol. (b) 191, 345 (1995); Phys. Rev. Lett. 77, 896 (1996); and Proc. Internat. Conf. Exciton Processes in Condensed Matter, World Scientific, Singapore 2000, respectively], (para-)excitons in Cu 2 O have been detected electrically by their field ionization in a Schottky barrier. We analyze the electric field in the Schottky barrier and its screening by the holes remaining after field ionization and find serious screening and saturation effects of this Schottky-barrier exciton detector under the excitation conditions of the experiment. These findings make a reinterpretation of the data very likely. IntroductionExcitons are the quanta of the collective excitation of the electron system in semiconductors and insulators. This excitation can be described to a very good approximation as a two-particle state, consisting of an electron in the conduction band and of the hole left behind in the valence band plus Coulomb and exchange interaction between these two particles. In so far the problem is closely related to the hydrogen or the positronium atom (see, e.g., [4,5], and references therein). Obviously the exciton is an electrically neutral quasiparticle with integer spin, but it is composed of two fermions, namely electron and hole. As a consequence of this fact, the commutation relations between exciton creation and annihilation operators are those of bosons at low densities, but with a deviation from ideal boson character via a term which increases with the density of excitons [4].The interplay of bosonic character and fermionic constituents triggered a lot of research over several decades about what happens with excitons at the highest densities. In the following we summarize shortly the present situation for bulk semiconductors. It became clear that at the highest densities a transition to a metallic electron-hole plasma (EHP) occurs [4][5][6]. Depending on the material parameters and excitation conditions such as carrier lifetime, excitation density, and carrier temperature, the plasma may even undergo a first-order phase transition to a liquid-like state, the analogon to molten metallic hydrogen. This is even true in CuCl [7] in spite of its large exciton binding energy and small Bohr radius, shifting the density for the occurrence of an EHP (also called Mott density) from values below 10 17 cm À3 , e.g., for Ge to very high values around 10 20 cm À3 . Experimental investigations and the theoretical modelling of the electron-hole plasma have been pushed by many research groups world-wide as can be seen, e.g., from the references in reviews and textbooks like [4,5]. These refer-

show abstract

“…This may be due to a leak in parallel to the barrier the origin of which is not always clear. In some cases it was suggested that metallic precipitates form this parallel path [13,14]. In a recent publication these "leaking" Schottky I-V relations were observed again and fitted by [8].…”

Section: Israelmentioning

confidence: 90%

Semi-Conductors with Mobile Ions Show a New Type of I-V Relations

et al. 2005

View full text Add to dashboard Cite

Semi-conductors with mobile acceptors or donors show a new type of I-V relations. This paper presents experimental results for solid state devices based on copper oxide, found to be Cu 2 O, which exhibit these I-V relations. The cells examined are Cu|Cu 2 O|In and Cu|Cu 2 O|Ag and similar ones tested at room temperature. The measured I-V relations are different from those reported for the same type of cells in the past, which were explained to be fixed by a Schottky barrier Cu|Cu 2 O. We find that the I-V relations relax over a long time which we claim is due to ion redistribution. The new I-V relations can then be explained by assuming that Cu 2 O is a mixed-ionicelectronic-conductor and adopting a theory developed by us in the past and modified to be applicable to the relevant defect model here. In this case the contribution of Schottky barriers is insignificant.

show abstract

Cuprous oxide-copper photovoltaic cells formed by high-temperature reduction

Cited by 5 publications

References 6 publications

Study of Anomalous Excitonic Transport in Cu₂O

Study of Anomalous Excitonic Transport in Cu₂O

Some Considerations Concerning the Detection of Excitons by Field Ionization in a Schottky Barrier

Semi-Conductors with Mobile Ions Show a New Type of I-V Relations

Contact Info

Product

Resources

About

Cuprous oxide-copper photovoltaic cells formed by high-temperature reduction

Cited by 5 publications

References 6 publications

Study of Anomalous Excitonic Transport in Cu2O

Study of Anomalous Excitonic Transport in Cu2O

Some Considerations Concerning the Detection of Excitons by Field Ionization in a Schottky Barrier

Semi-Conductors with Mobile Ions Show a New Type of I-V Relations

Contact Info

Product

Resources

About

Study of Anomalous Excitonic Transport in Cu₂O

Study of Anomalous Excitonic Transport in Cu₂O