On the zeros of the solutions of $y”+P(z)y=0$ where $P(z)$ is a polynomial

Lei, Shen

doi:10.1090/s0002-9939-1993-1132424-8

Cited by 29 publications

(46 citation statements)

References 3 publications

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“…Up to now, only few numerical simulations concerning passivation of local contacts have been carried out. These simulations demonstrate that a sufficiently thick local BSF layer is needed to achieve low values for SRV . This requirement is fulfilled in the case of filled contacts where in general a BSF layer with a thickness of several micrometres exists.…”

Section: Introductionmentioning

confidence: 74%

“…The application of scanning electron microscopy (SEM) has been a common method to categorize contacts and voids in particular . However, SEM imaging requires a high effort for sample preparation and the obtained cross‐sectional views give only little information concerning the spatial distribution of voids within a large area PERC solar cell.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of local Al‐contacts by light beam induced current measurements and their verification by 2D simulation using flexPDE

Horbelt

Micard

Keller

et al. 2016

Physica Status Solidi (a)

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In recent years the relevance of passivated emitter and rear contact solar cells for industrial application increased due to significantly higher cell efficiencies compared to full area back surface field solar cells. However, the formation of local Al contacts is particularly sensitive to the manufacturing process parameters. Under non-optimized conditions, the eutectic in local Al contacts is missing and so-called voids are formed. So far, their impact onto the electrical parameters of the solar cells is not fully understood, mainly because of their difficult spatially resolved detection. Within this work the application of scanning acoustic microscopy circumvents this difficulty and allows a classification of local contacts in terms of "voids" or "filled contacts" on large cell area. The passivation quality of the BSF in the local contacts is investigated in detail through the local internal quantum efficiency (IQE) measured by light beam induced current (LBIC). It is found that there is a large spreading for the IQE values, attributed to a variation in BSF layer thickness. In addition, LBIC measurements of voids are fitted by 2D simulations, according to a detailed modelling of the surface recombination velocities (SRV) in local contacts. The final model is based on a nonuniform SRV in the void's vicinity, attributed to laser damage close to the interface. It is demonstrated that the electrical parameters of the solar cell are affected by voids only when their surface is not sufficiently passivated by a local BSF.

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Section: Introductionmentioning

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Characterization of local Al‐contacts by light beam induced current measurements and their verification by 2D simulation using flexPDE

Horbelt

Micard

Keller

et al. 2016

Physica Status Solidi (a)

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“…Shen used EDTA as crystal modifier of phosphogypsum to prepare α‐hemihydrate phosphogypsum under 130°C with hydrothermal autoclave method. The research shows that pH can effect crystallization morphology significantly.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Large‐Grained α‐High Strength Gypsum with FGD Gypsum

Shao

Zhao

Zhang

et al. 2017

Crystal Research and Technology

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Using FGD gypsum as the raw material, short columnar‐shaped α‐calcium sulfate hemihydrate can be prepared with succinic acid in hydrothermal autoclave method with a low salt content. The influence of washing times, slurry concentration, salt content, reaction temperature, pH and the amount of succinic acid were investigated. The research shows that: short columnar α‐calcium sulfate hemihydrate with the length of 50 μm and length‐diameter ratio of 1, dry compressive strength of which is similar to 40 grade was obtained at the slurry concentration of 14%, salt content of 3%, succinic acid of 0.07% after three times washing under 115°C without the change of pH value. After 5 times circulation of mother liquid, the morphology of the product had no significant difference with the initial product and recycling rate of sodium chloride was not less than 90%.

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“…12 Various electronaccepting units such as benzothiadiazole (BT), 13 isoindigo, 14 diketopyrrolopyrrole (DPP), 15 thieno [3,4-c]pyrrole-4,6-dione (TPD), [16][17][18] and dyes such as rhodanine and indandione have been reported. 19 Recently, Heeney et al reported a series of dithienogermolodithiophene-based polymer donors containing various accepting units such as TPD, DPP, or BT. 20 They showed different UV absorption bands, molecular energy levels, degree of crystallinity, and, therefore, photovoltaic properties.…”

Section: Introductionmentioning

confidence: 99%

TPD‐ and DPP‐based Small Molecule Donors Containing Pyridine End Groups for Organic Photovoltaic Cells

Kim

Song

Lee

et al. 2016

Bulletin Korean Chem Soc

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We synthesized two new thieno [3,4-c]pyrrole-4,6-dione (TPD)-and diketopyrrolopyrrole (DPP)-based small molecules having pyridine end groups, TPDTPy and DPPTPy, using the Stille and Suzuki coupling reactions, respectively. The optical, electrochemical, and photovoltaic properties of these small molecules depended on the introduced electron-accepting units of TPD and DPP. DPPTPy exhibited a relatively low-energy bandgap (E g ) of 1.82 eV compared to TPDTPy (2.22 eV) because of the stronger electron-withdrawing ability of DPP compared to TPD. Organic photovoltaic cells with the inverted ITO/ZnO/small molecule:(6,6)-phenyl-C 71 -butyric acid methyl ester/MoO 3 /Ag structure were fabricated. The DPPTPy-based device showed a relatively high power conversion efficiency of 0.62% compared to TPDTPy (0.16%), mainly because of the red-shifted UV absorption, lower E g , and the higher short-circuit current of DPPTPy.

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On the zeros of the solutions of $y”+P(z)y=0$ where $P(z)$ is a polynomial

Cited by 29 publications

References 3 publications

Characterization of local Al‐contacts by light beam induced current measurements and their verification by 2D simulation using flexPDE

Characterization of local Al‐contacts by light beam induced current measurements and their verification by 2D simulation using flexPDE

Preparation of Large‐Grained α‐High Strength Gypsum with FGD Gypsum

TPD‐ and DPP‐based Small Molecule Donors Containing Pyridine End Groups for Organic Photovoltaic Cells

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