Optimization and improvement of a front graded bandgap CuInGaSe2 solar cell

Aissat, A.; Arbouz, H.; Vilcot, J.P.

doi:10.1016/j.solmat.2017.09.017

Cited by 20 publications

(7 citation statements)

References 21 publications

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“…The role of the Ga-profiles was also investigated by several simulation studies ,− that addressed different graded bandgap structures such as uniform, normal, linear, step, and double grading, among others, as well as Ga-dependent defect concentrations. These studies highlighted the importance of the shape of the bandgap profile on the performance of the solar cells, the value of the GGI minimum, and the position of the GGI minimum inside or outside the space charge region.…”

Section: Introductionmentioning

confidence: 99%

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

et al. 2020

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Depth bandgap profiles via a [Ga]/([Ga]+[In]) variation in the Cu(In,Ga)Se2 (CIGS) absorber layer have been implemented as a strategy to enhance the performance of CIGS solar cells. Since the [Ga]/([Ga]+[In]) determines to a large extent the position of the conduction band minimum, different Ga-profiles lead to different electronic energy levels structures throughout the CIGS layer. In this paper, from the investigation of the dependence of the photoluminescence (PL) on excitation power and temperature, we critically analyze the impact of a notch or a linear Ga-profile on the CIGS electronic energy levels structure and subsequent dominant recombination channels. Notwithstanding, two radiative transitions involving fluctuating potentials were observed for each sample, and significant differences in the luminescence resulting from the two Ga-profiles were identified. For the CIGS absorber with a notch Ga-profile, two tail-impurity radiative transitions involving equivalent donor clusters and the same deep acceptor level were ascribed to the CIGS/CdS interface region and to the notch region. The probability of radiative recombination in these two regions is discussed. For the CIGS absorber with a linear Ga-profile, two band-impurity radiative transitions involving an acceptor, with an ionization energy compatible with the V Cu defect were ascribed to the CIGS/CdS interface region. Our results show that the dominant acceptor defects are dependent on the Ga-profile, and they also highlight the complexity of the radiative and nonradiative recombination channels revealed by the tight control of the parameters in the experiment.

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Section: Introductionmentioning

confidence: 99%

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

et al. 2020

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“…Current record efficiencies of Cu(In,Ga)Se 2 (CIGS) thin films are over 23%, which is comparable with those of multicrystalline silicon cells. − In general, high-efficiency CIGS solar cells have a “V-shaped” Ga gradient. − The back gradient can produce an electric potential variation or affinity (conduction band) variation, which makes the electrons stay away from the rear contact and decreases recombination, leading to a higher short-circuit current density ( J sc ). − However, a steeper back gradient often significantly increases the Ga content (higher Ga composition) near the Mo layer, which reduces the grain size, increases lattice distortion, , and the concentration of bulk defects, such as antisite defects (Ga Cu ). These defects can form the photogenerated electrons trap, limit the open-circuit voltage ( V oc ), and deteriorate the device performance of CIGS solar cells. , Although a gentler back gradient can reduce lattice distortions, it also leads to a weak electric potential variation or affinity (conduction band) variation, which is adverse to the collection of minority carriers.…”

Section: Introductionmentioning

confidence: 99%

Facile Silver-Incorporated Method of Tuning the Back Gradient of Cu(In,Ga)Se₂ Films

Zhang

Lin

et al. 2020

ACS Appl. Energy Mater.

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An appropriate gallium (Ga) back gradient in Cu(In,Ga)Se 2 (CIGS) films is vital to achieve solar cells with good device performances. As a steeper Ga back gradient can induce an enhanced electric potential variation or affinity (conduction band) variation, it can make the electrons stay away from the rear contact. In addition, significant lattice distortions can be found at the back gradient of CIGS films, which increases carrier recombination and impedes carrier transport. In this study, by employing an Ag−Se precursor before the CIGS process, silver (Ag) is purposefully doped to the back gradient of CIGS films to reduce the lattice distortions. A comparison of the structure and device characteristics of CIGS films with different Ag−Se deposition durations is carried out. This study suggests that the addition of an Ag−Se precursor can enhance the quality of the CIGS film and modify the back gradient as well as enhance recrystallization, which improves the device performance of solar cells. Simultaneously, the enhanced grain sizes achieved by the Ag-treated process are helpful for the improvement of carrier mobility and the reduction of boundary recombination in CIGS films. Furthermore, the accumulation of indium caused by the Ag−Se precursor film in the first stage should contribute to the formation of a modified back gradient. This work offers an easy route for the control of the Ga back gradient in CIGS thin film solar cells.

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“…When two different layers are stacked together, a generation of a built-in voltage offset ( V bi ) can be observed. The expression of this entity is given below. , V bi = E normalg 2 − E normalg 1 …”

Section: Methodsmentioning

confidence: 99%

Design of Aluminum Doped ZnO/Phenyl-C-Butyric Acid Methyl Ester/Tungsten Disulfide (AZO/PCBM/WS₂) Heterojunction-Based Device for Applications in Solar Cells and Broadband Self-Powered Photodetectors

Sinha

2024

Langmuir

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The domain related to the use of renewable energy is showing high interest among the researchers in the current days, and light energy can be considered as one of such. Solar cells are the kind of devices that use light energy in an efficient way to generate electricity. Hence, designing and developing a solar cell requires meticulous attention to get an optimum output. This work focuses on designing and optimization of aluminum dope ZnO/phenyl-C-butyric acid methyl ester/tungsten disulfide (AZO/PCBM/WS2) heterojunction-based device for applications in solar cells. Moreover, considering the high demand of optoelectronics like photodetectors, this work also uncovers the capabilities of the device in the applications of broadband self-powered photodetectors. The optimized values of several parameters of the device such as the thickness and doping density of the WS2 layer, the defect density of the WS2 layer, and the interface PCBM/WS2 were 2 μm, 1017 cm–3, 1014 cm–3, and 1010 cm–2, respectively. These optimal conditions facilitated in obtaining fill factor and efficiency values of 84.78 and 23.92%, respectively. Further, the photodetection performance was evaluated with the parameters like responsivity and detectivity. The maximum calculated responsivity of the device at 0 V bias was 0.63 A/W at 880 nm, whereas the maximum detectivity was 1.54 × 1013 Jones. This study also extensively focuses on the in-depth understanding of the physics associated with the movement of the charge carriers under the illuminated conditions by studying the band diagrams and the electric fields of the heterojunctions at various conditions.

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Optimization and improvement of a front graded bandgap CuInGaSe2 solar cell

Cited by 20 publications

References 21 publications

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

Facile Silver-Incorporated Method of Tuning the Back Gradient of Cu(In,Ga)Se₂ Films

Design of Aluminum Doped ZnO/Phenyl-C-Butyric Acid Methyl Ester/Tungsten Disulfide (AZO/PCBM/WS₂) Heterojunction-Based Device for Applications in Solar Cells and Broadband Self-Powered Photodetectors

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Optimization and improvement of a front graded bandgap CuInGaSe2 solar cell

Cited by 20 publications

References 21 publications

Recombination Channels in Cu(In,Ga)Se2 Thin Films: Impact of the Ga-Profile

Recombination Channels in Cu(In,Ga)Se2 Thin Films: Impact of the Ga-Profile

Facile Silver-Incorporated Method of Tuning the Back Gradient of Cu(In,Ga)Se2 Films

Design of Aluminum Doped ZnO/Phenyl-C-Butyric Acid Methyl Ester/Tungsten Disulfide (AZO/PCBM/WS2) Heterojunction-Based Device for Applications in Solar Cells and Broadband Self-Powered Photodetectors

Contact Info

Product

Resources

About

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

Recombination Channels in Cu(In,Ga)Se₂ Thin Films: Impact of the Ga-Profile

Facile Silver-Incorporated Method of Tuning the Back Gradient of Cu(In,Ga)Se₂ Films

Design of Aluminum Doped ZnO/Phenyl-C-Butyric Acid Methyl Ester/Tungsten Disulfide (AZO/PCBM/WS₂) Heterojunction-Based Device for Applications in Solar Cells and Broadband Self-Powered Photodetectors