Stationary State of a Semiconductor with Negative Bulk Differential Conductivity

In CdS, unstable moving domains are observed, which exist in a current-voltage range between the range for stationary electrode-adjacent domains and the range for transitions to undeformed moving domains. These current -voltage ranges have been investigated in the same crystal by changing the electron concentration a t the boundary of a pseudocathode. Several CdS crystals, differently doped with Ag, Al, and &, have been investigated. An electro-optical method using the Franz-Keldysh effect was employed for domain observation. The influence of the distance between the electrodes on domain formation is discussed.I n CdS werden nichtstabile, wandernde Domiinen beobachtet, die in einem StromSpannungs-Bereich existieren, der zwischen dem Bereich der stationiiren, an der Elektrode anliegenden Domiinen und dem Ubergangsbereich zu undeformierten, wandernden Domiinen liegt. Diese Strom-Spannungs-Bereiche wurden in demselben Kristall durch hnderung der Elektronenkonzentration an der Grenzschicht einer Pseudokathode untersucht. Verschiedene CdS-Kristalle, .die unterschiedlich mit Ag, Al und Cu dotiert waren, wurden untersucht. Eine elektro-optische Methode, die den Franz-Keldysh-Effekt ausnutzt, wurde fur die Beobachtung der Domiinen verwendet. Der EinfluD des Elektrodenabstandes auf die Domiinenausbildung wird diskutiert.

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“…Curve 1 in Fig. 3 gives an indication that this is correct even for rather long crystals (see also [20]). …”

Section: Ulv -mentioning

confidence: 79%

Transition between Stationary and Moving High‐Field Domains in CdS in a Range of N‐Shaped Negative Differential Conductivity due to Field‐Quenching

Böer

Voss

1968

Physica Status Solidi (b)

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“…In most n-type materials a high-field domain usually stays adjacent to the cathode [9, 10, la]. (In n-type Ge with ohmic contacts, however, only anodeadjacent high-field domains have been observed [15]. ) It is the purpose of this paper to analyse systematically the conditions under which stationary high-field domains will occur adjacent t o cathode or anode.…”

Section: Introductionmentioning

confidence: 99%

Stationary Anode‐Adjacent High‐Field Domains in Cadmium Sulfide

Böer

Voss

1968

Physica Status Solidi (b)

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It is shown that, in n-type material with negative differential conductivit,y due to field quenching, st'ationary cathodeor anode-adjacent high-field domains occur dependent on electron density a t the cathode and applied voltage. Cathode-adjacent high-field domains can be observed only with a blocking cathode. Anode-adjacent high-field domains occur with a slightly blocking cathode a t applied voltages above the range a t which cathodeadjacent domains are observed or as the only domain type possible with an injecting cathode. With different cathode metals evaporated onto the same CdS :Ag, A1 crystal the electron density in the conduction band n,(E) for space charge free conditions has been determined as a function of the actual field between 0 and 240 kV/cm.Es wurde gezeigt, da13 in n-leitendem Material mit negativ differentiellem Widerstand, der durch Feldtilgungseffekte verursacht ist, stationare Hochfelddomanen an der Kathode oder Anode in Abhangigkeit von der Elcktronenkonzentration an der Kathode und von der angelegten Spannung auftret,en. Hochfelddomanen an der Kathode konnen nur mit blockierender Kathode beobachtet werden. Hochfelddomanen an der Anode treten bei einer schwach blockierenden Kathode auf, wenn die angelegte Spannung oberhalb des Bereiches der Hochfelddomanen an der Kathode liegt, oder sie treten als einzig moglicher Domanentyp bei injizierender Kathode auf. Mit verschiedenen Kathodenmaterialien, die auf denselben (CdS :Ag, A1)-Kristall aufgedampft waren, wurde die Elektronenkonzentration im Leitungsband n,(E) fur den raumladungsfreien Fall als Funktion der wirkenden Feldstarke zivischen 0 und 240 kV/cm bestimmt.Supported by the U.S. Office of Naval Research, Washington, D.C.2, A discussion about the transition between stationary and moving domains is given by Kroll (submitted to phys. stat. sol.). 23'

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“…Between 0°K and room temperature E c increases by only 2.4%. 6 In Fig. 1 we plot the normalized plasma frequency fi p versus T, for the concentration n = n c°, between 0°K and room temperature.…”

Section: Plasmaj'frequencymentioning

confidence: 99%

Intervalley Transfer, Plasma Frequency, and Plasmon-LO-Phonon Interaction inn-Type Gallium Antimonide

Omar

1969

Phys. Rev.

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A theoretical study is made of the effects of intervalley transfer on the plasma frequency and plasmon-LO-phonon interaction in highly doped n-type gallium antimonide. Because of the difference in masses between the central and secondary valleys, both the plasma frequency and the plasmon-phonon interaction undergo large changes when an appreciable transfer from the central to the secondary valleys occurs as a result of raising the temperature from 0°K to room temperature.

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Stationary State of a Semiconductor with Negative Bulk Differential Conductivity

Cited by 13 publications

References 11 publications

Transition between Stationary and Moving High‐Field Domains in CdS in a Range of N‐Shaped Negative Differential Conductivity due to Field‐Quenching

Transition between Stationary and Moving High‐Field Domains in CdS in a Range of N‐Shaped Negative Differential Conductivity due to Field‐Quenching

Stationary Anode‐Adjacent High‐Field Domains in Cadmium Sulfide

Intervalley Transfer, Plasma Frequency, and Plasmon-LO-Phonon Interaction inn-Type Gallium Antimonide

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