Charge Transport Mechanisms and Device Parameters of CdS/CdTe Solar Cells Fabricated by Thermal Evaporation

CdTe semiconductor is an absorbent material used in “tandem” photovoltaic solar cells. This material is commonly deposited by thermal evaporation presenting electrical resistivity values about of 105 W·cm to 109 W·cm. CdTe is applied in thin solar cells as p-type layer which is in contact with metal back electrode in solar cells. In the CdTe/metal junction a Schottky barrier exits; and small number of charge carriers have enough energy to get over the barrier and cross to the metal back contact. To solve part of this problem, nanostructured Te thin films were used as intermediate layers between CdTe and metal contact. Te layers whit different physical properties were deposited on CdS/CdTe structure by thermal evaporation employing different growth parameters. The electrical parameters of CdTe solar cells were influenced by p+ Te regions. p+ Te regions used as intermediate layer with large deposition time increases the FF and VOC values from 30% to 60% and 560 mV to 730 mV respectively. Also, the electrical resistivity is reduced from 106 W·cm to 103 W·cm. In this sense, Te region implemented as nanostructure allows to reduce the series resistance from 99 W to 20 W and increases the shunt resistance from 1445 W to 4424 W; Te region as thin films demonstrated not be adequate.

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Defect passivation and humidity protection for perovskite solar cells enabled by 1-dodecanethiol

Journal of Materials Chemistry C ◽

10.1039/d1tc01720a ◽

2021 ◽

Author(s):

Dingchao He ◽

Xiao-Xiao Xu ◽

Zheng Liang ◽

Yunjuan Niu ◽

Yuan Sun ◽

...

Keyword(s):

Solar Cells ◽

Charge Transport ◽

Perovskite Solar Cells ◽

High Humidity ◽

Transport Mechanisms ◽

Multiple Defects ◽

Defect Passivation ◽

Film Preparation ◽

High Humidity Environment ◽

Humidity Environment

Multiple defects are prone to be produced during perovskite film preparation and exposure to high humidity environment, which would negatively affect charge transport mechanisms and finally degrade perovskite solar cells...

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Numerical Investigation of Graphene as a Back Surface Field Layer on the Performance of Cadmium Telluride Solar Cell

Molecules ◽

10.3390/molecules26113275 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3275

Author(s):

Devendra KC ◽

Deb Kumar Shah ◽

M. Shaheer Akhtar ◽

Mira Park ◽

Chong Yeal Kim ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Doping Concentration ◽

Carrier Lifetime ◽

Short Circuit ◽

Back Surface ◽

Back Surface Field ◽

Cdte Solar Cell ◽

Cdte Solar Cells ◽

Surface Field

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (h = 15%), and quantum efficiency (QE ~ 85%) were achieved at a carrier lifetime of 1 × 103 ms and a doping concentration of 1 × 1017 cm−3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 mm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication.

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