Ultraviolet Intrinsic and Extrinsic Photoconductivity of Natural Diamond

Denham, Pamela; Lightowlers, E C; Dean, P. J.

doi:10.1103/physrev.161.762

Cited by 112 publications

(23 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A photoconductivity threshold at 4.04 eV has been observed in type Ia and type lla diamonds [21], but not in type lib material in which the acceptors predominate. Photo-Hall measurements showed that the carriers involved in the photoconductivity were electrons [21]. No photoconductivity threshold is observed at 4 eV in type Ib diamond [19], and Davies [22] therefore speculates that the 4 eV donor may be the A aggregate of nitrogen.…”

Section: The Electronic Properties Of Diamondmentioning

confidence: 97%

“…Specimens which contain aggregated nitrogen as the major impurity, but at too low a concentration to be detected by conventional infrared absorption spectroscopy, are termed type Ia. A photoconductivity threshold at 4.04 eV has been observed in type Ia and type lla diamonds [21], but not in type lib material in which the acceptors predominate. Photo-Hall measurements showed that the carriers involved in the photoconductivity were electrons [21].…”

Section: The Electronic Properties Of Diamondmentioning

confidence: 98%

See 1 more Smart Citation

The Electronic and Optical Properties of Diamond; Do they Favour Device Applications?

Collins

1989

MRS Proc.

View full text Add to dashboard Cite

The electronic and optical properties of diamond are reviewed, with particular emphasis on current research into the production of semiconducting devices. Although many of the properties of diamond seem, at first sight, to be ideally suited to the development of high power microwave and optoelectronic devices, there are also a number of obstacles to be overcome before diamond may be successfully exploited for device applications.

show abstract

Section: The Electronic Properties Of Diamondmentioning

confidence: 97%

Section: The Electronic Properties Of Diamondmentioning

confidence: 98%

The Electronic and Optical Properties of Diamond; Do they Favour Device Applications?

Collins

1989

MRS Proc.

View full text Add to dashboard Cite

show abstract

“…Photoconductivity spectra 5 and photoluminescence excitation spectra 6 in several semiconductors show characteristic oscillations which demonstrate that process (1) dominates. However, the precise interpretation of the oscillatory structure in photoconductivity spectra is still controversial and undecided.…”

Section: R Ulbrich Physikalisches Institut Der Universitat Frankfurtmentioning

confidence: 97%

Capture of Hot Electrons by Ionized Donors in GaAs

Ulbrich

1971

Phys. Rev. Lett.

View full text Add to dashboard Cite

Investigation of photoluminescence excitation spectra in GaAs proves that the capture of hot conduction-band electrons by ionized donors via emission of LO phonons is an efficient relaxation mechanism.The relaxation of photoexcited hot electrons in a semiconductor can proceed via different mechanisms: emission of (1) optical phonons and (2) acoustical phonons, leading to final states within the conduction band, 1 ' 2 (3) cascade capture into impurity states through phonon emission, 3 and (4) radiative recombination with holes, 4 leading to final states at impurities or in the valence band. Photoconductivity spectra 5 and photoluminescence excitation spectra 6 in several semiconductors show characteristic oscillations which demonstrate that process (1) dominates. However, the precise interpretation of the oscillatory structure in photoconductivity spectra is still controversial and undecided. 5 ' 7 This Letter reports the first excitation spectra (ES) of the near-band-edge luminescence in GaAs. The conduction-band-acceptor (e,A°) and the donor-acceptor (D°, A 0 ) luminescence intensities serve as selective probes for the free-electron and the neutral-donor populations. The structure found in the luminescence ES demonstrates that the capture of hot electrons into donor states by emission of LO phonons is an efficient relaxation process, competing with thermalization into the bottom of the conduction band by emission of acoustical phonons. Lifetime measurements and line-shape analysis of the (e, A 0 ) luminescence set an upper limit to the intraband acoustical relaxation time for hot electrons, which is found to be considerably smaller than the lifetime of electrons in the conduction band. This result contradicts earlier assumptions. 8High-purity, epitaxially grown w-type GaAs samples with carrier concentrations in the range !.8xl0 12^r a^7.0xl0 14 cm" 3 (77 K) were used. Seven samples were investigated which all exhibited similar luminescence and excitation spectra. Sample £292 had a Hall mobility J LL = 148 000 cm 2 / Vsec and rc = 1.8xl0 13 cm' 3 at 77 K. Values of A^ = 1.2xl0 14 cm" 3 and N A = 1.0xl0 14 cm*" 3 have been calculated 9 from these data. The samples were immersed in liquid helium. Light from a 3400-K tungsten-iodine lamp was passed through a i-m grating monochromator and focused onto the sample. An excitation power density of 3 xlO" 6 W/cm 2 at 8000 A (bandwidth 14 A) was obtained. All ES were corrected for the smooth spectral distribution of the exciting radiation. The luminescence from the excited surface was dispersed by a f-m grating spectrometer and detected with a C31000E photomultiplier. Chopped (560 Hz) and dc excitation gave identical results.The luminescence spectrum of sample £292 near 1.49 eV is shown in the inset of Fig. 1. The luminescence bands (e,A°) at 1.4923 eV, and (D°, A 0 ) at 1.4883 eV have been identified by Rossi et al}° No other intense luminescence beside the free and bound exciton lines and the (e,A°) and (D°,A°) emission bands was present in the nearband-edge region. Pe...

show abstract

“…These detectors present a very low dark current due to their high intrinsic theoretical resistivity 1013 to 1015 f) m or more [8] [16]. The dark current measurement must be done very carefully, because the air insulation is lower than such high resistivity materials.…”

Section: -Dark Currentmentioning

confidence: 99%

Experimental Results in Picosecond and Subpicosecond Range of IIa Type Diamond Detector in X-UV, Visible and Ir Fields

et al. 1993

View full text Add to dashboard Cite

Type Ila diamonds present photoconductive properties as well in X-ray detection range, as in near UV, visible, IR light range, in spite of the large bandgap of the material. Experimental results in these four fields, time measurements in picosecond and subpicosecond ranges are presented. I -INTRODUCTIONDiamond photoconductive detectors have already been used to measure the burn time on laser fusion experiments [1] [2]. They can also be devoted to measure X-ray radiation emitted from laser induced plasmas [31 [41 . Due to the 5.5 eV band gap of diamond intrinsic conductivity, we can expect they will not be sensitive to scattered laser radiation. Unfortunately, natural diamond presents a lot of impurities and its conductivity is nonnegligible for photon energies below the intrinsic band gap. One of the aims of this paper is to present the diamond sensitivities to 1064 nm (co), 532 nm (2 o)) and 355 nm (3 co) laser radiation wavelengths and to compare them with the X-ray radiation sensitivity. Another is to show the fast temporal response of such detectors. -DETECTOR DESIGN -GeometryPhotoconductive devices have been fabricated from Ila natural diamond (Dricker International Netherlands). They consist of two different sizes small cylinders : 3 mm diameter by 2 mm height for the first one and 5 mm in diameter by 3 mm high for the second one. They have been set by LETI (CEA, Grenoble, France) at the end of a 50 0l KS 2 or KS 3 semi rigid coaxial cable.as shown on Figure 1. Top and bottom electrodes are made of Ti/Pt/Au coating. This geometry is not so convenient to measure X-ray radiation but these detectors were previously designed for neutron measurement [2].The electrodes are realized on the plane faces of the crystal . The upper electrode is connected to the outer conductor of the coaxial cable and the bottom electrode to its inner conductor. To allow the input of the laser light or the X-ray radiation, a 1mm wide slit is made in the cable outerdacket, along the diamond crystal thickness. The detector bandwidth depends on the carrier life times and its capacity, LETI calculations [5] predict capacity values of 0.2 pf and 0.36 pf (figure 2) for KS2 and KS3 cable geometries.The corresponding risetime values x are respectively 22 ps and 40 ps (with Mat.

show abstract

Ultraviolet Intrinsic and Extrinsic Photoconductivity of Natural Diamond

Cited by 112 publications

References 30 publications

The Electronic and Optical Properties of Diamond; Do they Favour Device Applications?

The Electronic and Optical Properties of Diamond; Do they Favour Device Applications?

Capture of Hot Electrons by Ionized Donors in GaAs

Experimental Results in Picosecond and Subpicosecond Range of IIa Type Diamond Detector in X-UV, Visible and Ir Fields

Contact Info

Product

Resources

About