Plasma frequency and dielectric function dependence on doping and temperature for p-type indium phosphide epitaxial films

Jayasinghe, R. C.; Lao, Yan-Feng; Perera, A. G. U.; Hammar, Mattias; Cao, Chunfang; Wu, Hui

doi:10.1088/0953-8984/24/43/435803

Cited by 23 publications

(5 citation statements)

References 37 publications

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“…The carrier concentration can be further estimated from experimental data by applying the Drude–Lorentz model or the Pisarenko relationship . Properties of degenerate semiconductors such as In 2 O 3 :Sn (ITO) and InP have been successfully modeled using the Drude–Lorentz model, while the Pisarenko relationship has been used for thermoelectric materials such as PbTe and Cu 2 GeS 4 . The Drude–Lorentz model is specified as

ω_{normalp} = \frac{E_{normalp}}{h} = \sqrt{\frac{N q^{normal2}}{ϵ_{0} ϵ_{\infty} m^{normal*}}}

where ω p is the plasma angular frequency, E p is the plasma energy centered at 0.8 eV in the absorbance plot shown in Figure b, h is Planck's constant, N is the carrier concentration, q is the elementary charge, ϵ 0 is the dielectric constant of free space, ϵ ∞ is the high frequency relative dielectric constant equal to 8.1 for Cu 12 Sb 4 S 13 , and m* is the hole effective mass estimated from band structure assessment as 1.3 m e .…”

Section: Resultsmentioning

confidence: 99%

Design Meets Nature: Tetrahedrite Solar Absorbers

Heo

Ravichandran

Reidy

et al. 2014

Advanced Energy Materials

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used to guide the selection and design of new absorbers using computational techniques. This metric captures the leading physics of absorption relevant to PV efficiency, and it improves upon the simple Shockley-Queisser bandgap model [ 7 ] by considering the full absorption spectrum of the absorber. Hence, SLME should be effective for guiding the selection and design of new ultrathin absorber materials for study and use in drift-aided cells. We have applied the SLME approach to the analysis of all ternary chalcogenides containing Cu, including materials in the system Cu-V-VI. [ 9 ] Several materials were found to exhibit SLME values much higher than those of conventional thin-fi lm absorbers.Subsequently, two general principles were formulated to guide the selection and design of new high-performance absorbers. [ 9 ] In the fi rst case, structural isolation of a Group-V atom in its 5+ oxidation state, e.g., Sb 5+ , within a Cu-rich matrix leads to a narrow Group-V-derived s-orbital band at the conduction band minimum (CBM). In combination with a narrow Cu d band at the valence band maximum (VBM), a high joint density of states and a high absorption coeffi cient ensue. In the second case, if the Group-V atom exists in the lower 3+ oxidation state, e.g., Sb 3+ , it adopts an ns 2 valence electron confi guration. In this 3+ oxidation state, highly asymmetric coordination environments can lead to long distances between the Group-V atoms, resulting in fl at bands and attendant high joint densities of states. These features contribute to an abrupt absorption onset and a high absorption coeffi cient. Strong absorption is reinforced by the parity-allowed nature of the electric-dipole V s or Cu d → V p transition. Hence, the second design principle focuses on structurally isolating the lower oxidation state Group-V element in a semiconducting matrix. Results and DiscussionThese considerations have led us to consider the mineral tetrahedrite, i.e., Cu 12 Sb 4 S 13 , as the basis for a new family of solar absorbers. This material was not revealed as a candidate in the initial SLME search [ 9 ] of Cu-V-VI materials because it was computed to have a zero bandgap, i.e., it is a metal and not a semiconductor. This metallic behavior can readily be appreciated by considering the mixed oxidation-state nature of Cu 12 Sb 4 S 13 . A mixture of formal oxidation states Cu 2+ (d 9 ) and Cu 1+ (d 10 ) is required for charge neutrality, i.e., 10 of the 12 Cu atoms in the chemical formula Cu 12 Sb 4 S 13 are monovalent, while the remaining two Cu atoms are divalent. An incompletely fi lled d-valence band is expected to give rise to the observed degenerate (metallic) behavior, [10][11][12][13] consistent with the Computational inverse design and consequent experimental results allow for the identifi cation of new tetrahedrite-mineral compositions as promising absorber candidates in drift-based thin-fi lm solar cells. In device simulations, cell effi ciencies above 20% are modeled with absorber layers as thin as 250 nm. These new compositio...

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ω_{normalp} = \frac{E_{normalp}}{h} = \sqrt{\frac{N q^{normal2}}{ϵ_{0} ϵ_{\infty} m^{normal*}}}

Section: Resultsmentioning

confidence: 99%

Design Meets Nature: Tetrahedrite Solar Absorbers

Heo

Ravichandran

Reidy

et al. 2014

Advanced Energy Materials

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“…The temperature dependence of ½ p , ¸, and ¾ ¨for Ag and Au have been studied from room temperature to 650 K. Free-carrier intra-band absorption is an indirect process and is mediated by phonons providing the additional momentum required for the energy and momentum conservation and are responsible for the temperature dependence of optical properties of the material. 22) It is found that the experimental temperature-dependent ½ p , ¸, and ¾ ¨are fitted using the following empirical functions: 23)…”

Section: Temperature Dependent Propertiesmentioning

confidence: 99%

Dielectric function dependence on temperature for Au and Ag

Chen

Lee

Wang

2014

Jpn. J. Appl. Phys.

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The dielectric functions of Au and Ag are measured using a spectral ellipsometer. The temperature dependence parameters ωp, τ, and ε∞, in the Drude–Sommerfeld model have been studied. Furthermore, we provide an empirical function to describe the temperature dependence of the dielectric function for Au and Ag. The empirical function shows a good agreement with previous results. Through the empirical function, one can obtain the dielectric constant at arbitrary temperature and wavelength. This database is useful for the applications that use surface plasmon (SP) resonance at high temperatures, such as the plasmonic thermal emitter, SP-assisted thermal cancer treatment and so on.

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“…However, higher electron concentrations result in higher plasma frequencies, 36 limiting the optical transparency of incident light in the MWIR range. The dependency of plasma frequency on carrier concentration is provided by the following equation: 45 where n e is the carrier concentration, e is the charge of the carriers, m * is the effective mass of the carriers, and ε 0 is the permittivity of free space.…”

Section: Resultsmentioning

confidence: 99%

Low-cost uncooled MWIR PbSe quantum dots photodiodes

et al. 2019

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A mid-wave infrared (MWIR) uncooled PbSe-QDs/CdS p-n heterojunction photodiode has been fabricated using a wet-chemical synthesis route. This offers a low-cost alternative to traditional monocrystalline photodiodes relying on molecular beam epitaxy (MBE) technology. It was demonstrated that the postannealing is critical to tailor the photoresponse wavelength and to improve the performance of photodiodes. After annealing at 673 K in air for 0.5 h, the ligand-free PbSe-QDs/CdS photodiode exhibits a MWIR spectral photoresponse with a cutoff wavelength of 4.2 mm at room temperature. Under zerobias photovoltaic mode, the peak responsivity and specific detectivity at room temperature are 0.36 AE 0.04 A W À1 and (8.5 AE 1) Â10 8 cm Hz 1/2 W À1 , respectively. Temperature-dependent spectral response shows an abnormal intensity variation at temperatures lower than 200 K. This phenomenon is attributed to the band alignment transition from type II to type I, resulting from the positive temperature coefficient of PbSe. In addition, it was proved that In doped CdSe (CdSe:In) films could be used as a promising new candidate of infrared transparent conductive electrodes, paving the way for monolithic integration of uncooled low-cost MWIR photodiodes on Si readout circuitry. Fig. 2 Top-and cross-side view FESEM images of (a) as-grown, (b) and (e) 473 K, (c) and (f) 573 K, (d) and (g) 673 K annealed ligand-free PbSe-QDs synthesized from low-temperature CBD method on glass substrates. Red dotted lines indicate micro-cracks.42518 | RSC Adv., 2019,9,[42516][42517][42518][42519][42520][42521][42522][42523] This journal is

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Plasma frequency and dielectric function dependence on doping and temperature for p-type indium phosphide epitaxial films

Cited by 23 publications

References 37 publications

Design Meets Nature: Tetrahedrite Solar Absorbers

Design Meets Nature: Tetrahedrite Solar Absorbers

Dielectric function dependence on temperature for Au and Ag

Low-cost uncooled MWIR PbSe quantum dots photodiodes

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