Influence of As/group-III flux ratio on defects formation and photovoltaic performance of GaInNAs solar cells

Polojärvi, Ville; Aho, Arto; Tukiainen, Antti; Raappana, Marianna; Aho, Timo; Schramm, Andreas; Guina, Mircea

doi:10.1016/j.solmat.2016.01.024

Cited by 34 publications

(40 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the properties of these materials are very dependent on the growth conditions and post-growth thermal treatments [4][5][6][7]. Therefore, in order to obtain actual properties of the GaNAsSb alloy suitable for modeling purposes, several characterization techniques have been applied on GaNAsSb samples with doping levels in the range of 1•10 17 and 1•10 18 cm -3 for both n-type and p-type.…”

Section: Determination Of Ganassb Materials Parametersmentioning

confidence: 99%

“…Accordingly, in the following, we will use dilute nitride material diffusion lengths for the material (i.e. any Ga(In)NAs(Sb) material) similar to those already achieved experimentally [1,[4][5][6] (in the order of 10 times higher than the ones extracted from the EQE in Fig. 1.a) In order to usefully incorporate the Ga(In)NAs(Sb) into a 4Junction device, the demands on this material in terms of photocurrent are very high because this subcell receives the lowest spectral power density (the maximum photocurrent under ideal collection efficiency is 14.2 mA/cm 2 while for the other subcells it is about 16 mA/cm 2 ).…”

Section: Modeling the Performance Of 4-junction Solar Cellsmentioning

confidence: 99%

See 1 more Smart Citation

Modelling of lattice matched dilute nitride 4-junction concentrator solar cells on Ge substrates

Ochoa¹,

García²,

Lombardero³

et al. 2016

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Technology Computer Aided Design modeling is used to examine the performance under light concentration of a 4-J solar cell Ge-based that includes a 1-eV MBE-grown dilute nitride subcell. The 1-eV solar cell is modeled and examined by using material parameters extracted from detailed electro-optical characterization prior to be included into a multijunction structure. The modelling reveals the impact of the electric field-assisted collection in the performance of single junction solar cells and its effect when included in a 4-Junction solar cells. This effect is responsible for the lower FF (~15% lower) in the 4J when including the dilute nitride subcell, especially if it limits the photocurrent. Finally, an optimization procedure based on dilute nitrides with higher material quality is performed resulting in a 4-Junction solar cell with an efficiency of 47% for concentrations between 1000-2000 suns direct terrestrial spectrum.

show abstract

Section: Determination Of Ganassb Materials Parametersmentioning

confidence: 99%

Section: Modeling the Performance Of 4-junction Solar Cellsmentioning

confidence: 99%

Modelling of lattice matched dilute nitride 4-junction concentrator solar cells on Ge substrates

Ochoa¹,

García²,

Lombardero³

et al. 2016

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…, 15 and of non-radiative recombination centers. Post-growth annealing improves the quality of InGaAsN dilute nitrides.…”

Section: à3mentioning

confidence: 99%

“…It is worth noting that a p-type background doping is typical for i-layers of dilute nitrides (In)GaAsN grown by MBE. 14,15 Usually, it is associated with non-equilibrium growth conditions at low temperatures that lead to the formation of gallium vacancies and nitrogen-related defects of acceptor type in dilute nitrides but a complete description and explanation of background doping in InGaAsN layers should be investigated in further experiments. Nevertheless, in our InAs/GaAsN layers, the background doping values are several times lower than those found for InGaAsN layers grown by MBE without Sb in the articles cited above (more than 1.0 Â 10 16 cm…”

Section: à3mentioning

confidence: 99%

Defect properties of InGaAsN layers grown as sub-monolayer digital alloys by molecular beam epitaxy

Baranov

Gudovskikh

Kudryashov

et al. 2018

Journal of Applied Physics

View full text Add to dashboard Cite

The defect properties of InGaAsN dilute nitrides grown as sub-monolayer digital alloys (SDAs) by molecular beam epitaxy for photovoltaic application were studied by space charge capacitance spectroscopy. Alloys of i-InGaAsN (Eg = 1.03 eV) were lattice-matched grown on GaAs wafers as a superlattice of InAs/GaAsN with one monolayer of InAs (<0.5 nm) between wide GaAsN (7–12 nm) layers as active layers in single-junction solar cells. Low p-type background doping was demonstrated at room temperature in samples with InGaAsN layers 900 nm and 1200 nm thick (less 1 × 1015 cm−3). According to admittance spectroscopy and deep-level transient spectroscopy measurements, the SDA approach leads to defect-free growth up to a thickness of 900 nm. An increase in thickness to 1200 nm leads to the formation of non-radiative recombination centers with an activation energy of 0.5 eV (NT = 8.4 × 1014 cm−3) and a shallow defect level at 0.20 eV. The last one leads to the appearance of additional doping, but its concentration is low (NT = 5 × 1014 cm−3) so it does not affect the photoelectric properties. However, further increase in thickness to 1600 nm, leads to significant growth of its concentration to (3–5) × 1015 cm−3, while the concentration of deep levels becomes 1.3 × 1015 cm−3. Therefore, additional free charge carriers appearing due to ionization of the shallow level change the band diagram from p-i-n to p-n junction at room temperature. It leads to a drop of the external quantum efficiency due to the effect of pulling electric field decrease in the p-n junction and an increased number of non-radiative recombination centers that negatively impact lifetimes in InGaAsN.

show abstract

“…[8][9][10] High background doping level narrows the depletion region, which together with the short diffusion length limits the thickness of an optimized absorption layer, resulting in lower quantum efficiencies. [9][10][11][12] To obtain wider depletion regions and higher quantum efficiencies, the p-type background doping should be reduced down to the order of 10 15 cm À3 or below, which still remains a challenging task at high N compositions (y ! 0.04).…”

mentioning

confidence: 99%

Enhancement of photocurrent in GaInNAs solar cells using Ag/Cu double-layer back reflector

Aho

Tukiainen

et al. 2016

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

The effect of a Ag/Cu-based double-layer back reflector on current generation in GaInNAs single-junction solar cell is reported. Compared to Ti/Au reflector, the use of Ag/Cu led to a 28% enhancement of short-circuit current density, attaining a value of ∼14 mA/cm2 at AM1.5D (1000 W/m2) under a GaAs filter. The enhanced current generation is in line with requirements for current-matching in GaInP/GaAs/GaInNAs triple-junction solar cells. The Ag/Cu reflectors also had a low contact resistivity of the order of 10−6 Ω·cm2 and none of the samples exhibited notable peeling of metals in the adhesion tests. Moreover, no discernible diffusion of the metals into the semiconductor was observed after thermal annealing at 200 °C.

show abstract

Influence of As/group-III flux ratio on defects formation and photovoltaic performance of GaInNAs solar cells

Cited by 34 publications

References 41 publications

Modelling of lattice matched dilute nitride 4-junction concentrator solar cells on Ge substrates

Modelling of lattice matched dilute nitride 4-junction concentrator solar cells on Ge substrates

Defect properties of InGaAsN layers grown as sub-monolayer digital alloys by molecular beam epitaxy

Enhancement of photocurrent in GaInNAs solar cells using Ag/Cu double-layer back reflector

Contact Info

Product

Resources

About