30×40 cm2 flexible Cu(In,Ga)Se2 solar panel by low temperature plasma enhanced selenization process

Severe Ga accumulation at the back contact is regarded as one of the major limiting factors for high efficiency Cu(In,Ga)Se2 (CIGSe) solar cells fabricated by the sequential process. The Ga deficiency near the front surface of absorber leads to the reduction of open‐circuit voltage; however, controlling the Ga grading is quite challenging during the selenization process. Herein, the tuning of Ga profile is demonstrated by forming the ordered vacancy compound (OVC) phase at the beginning of selenization process under high Se partial pressure (PSe) with the precursor composed of a relatively high In content. The OVC phase formed with a columnar structure promotes Ga diffusion through Cu vacancies, resulting in Ga increase at the front side of CIGSe. However, high PSe also increases the thickness of MoSe2, significantly raising the series resistance. Thereby, a 5 nm TiN layer is deposited on top of Mo to suppress the formation of MoSe2. In addition, the extra Na‐contained precursor is added to increase the carrier concentration because the TiN layer also blocks the Na outdiffusion from the substrate. By controlling PSe, interlayer TiN thickness, and carrier concentration, a 16.04% record high efficiency of CIGSe solar cells (sulfur‐free) via elemental Se source is achieved.

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“…The further efficiency improvement is expected by increasing the activity of Se with the Se cracker source or plasma‐enhanced Se vapor. [ 31 ]…”

Section: Resultsmentioning

confidence: 99%

Tuning Ga Grading in Selenized Cu(In,Ga)Se₂ Solar Cells by Formation of Ordered Vacancy Compound

Cai

Lai

2020

Solar RRL

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“…ECD of Cu-In-Ga has been reported by other groups in the past [6,8,9]. When this deposition method is used, a pre-annealing stage without chalcogen is commonly applied prior to the chalcogenisation itself [10][11][12], both on electroplated [12,13] and sputtered precursors [14]. Sometimes this heating stage is only intended to have a sample hot enough when it enters the selenium atmosphere [15].…”

Section: Introductionmentioning

confidence: 99%

In-situ X-ray diffraction annealing study of electroplated and sputtered Cu-In-Ga precursors for application to sequential Cu(In,Ga)Se2 processes

Aninat¹,

Hovestad²,

Zelst³

et al. 2022

Thin Solid Films

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“…Therefore, a range of processes have been assessed. Table presents representative cases where the small area solar cell efficiency is 10% or more . On the other hand, because Se vapor has different characteristics from general gas, several problems can be encountered when it is supplied in the vapor state when attempting to obtain a uniform heat treatment result.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, delicate process control is required to avoid nozzle cloaking, and there is still concern regarding the non‐uniform distribution of Se in the nozzle array direction. A successful case using Se vapor in a 300 × 400 mm 2 large area process was obtained from the activation of Se using plasma . Unfortunately, the additional equipment investment needed to discharge the inductively coupled plasma may reduce its applicability to mass production.…”

Section: Introductionmentioning

confidence: 99%

Two‐step selenization using nozzle free Se shower for Cu(In,Ga)Se₂ thin film solar cell

Song

Kang

Baek

et al. 2017

Progress in Photovoltaics

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The production of commercialized Cu(In,Ga)(S,Se) 2 (CIGS) photovoltaic absorber layers uses expensive H 2 Se gas with a high utility cost. To reduce the manufacturing cost of CIGS photovoltaic modules, a process technology capable of supplying Se vapor uniformly over a large area is required to replace H 2 Se. In this study, a nozzle-free Se shower was implemented using a porous material to pass Se vapor while confining liquid Se, and the highly effective selenization of the CuInGa precursor was performed. The nozzle-free Se-shower vehicle could be mounted in a commercial rapid thermal process chamber. The chamber pressure and the temperatures of the shower module and substrate, which were controlled independently by the upper and lower heaters, respectively, were varied to control the amount of Se supplied during the entire selenization reaction in real time. In particular, the precursor should be soaked with a sufficient amount of Se at a relatively low substrate temperature of 300°C or less to obtain a good quality absorber. In addition, at a chamber pressure of 100 Torr during the soaking stage, the Ga content in the surface region of the absorber increased considerably with a concomitant improvement in the open-circuit voltage. The highest performance obtained using this method was an open-circuit voltage of 0.638 V, short-circuit current density of 34 mA/cm 2 , fill factor of 67.2%, and an active area efficiency of 14.57%. This performance is very high compared with other CIGS solar cells manufactured by a 2-step process using Se vapor.

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30×40 cm2 flexible Cu(In,Ga)Se2 solar panel by low temperature plasma enhanced selenization process

Cited by 14 publications

References 18 publications

Tuning Ga Grading in Selenized Cu(In,Ga)Se₂ Solar Cells by Formation of Ordered Vacancy Compound

Tuning Ga Grading in Selenized Cu(In,Ga)Se₂ Solar Cells by Formation of Ordered Vacancy Compound

In-situ X-ray diffraction annealing study of electroplated and sputtered Cu-In-Ga precursors for application to sequential Cu(In,Ga)Se2 processes

Two‐step selenization using nozzle free Se shower for Cu(In,Ga)Se₂ thin film solar cell

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30×40 cm2 flexible Cu(In,Ga)Se2 solar panel by low temperature plasma enhanced selenization process

Cited by 14 publications

References 18 publications

Tuning Ga Grading in Selenized Cu(In,Ga)Se2 Solar Cells by Formation of Ordered Vacancy Compound

Tuning Ga Grading in Selenized Cu(In,Ga)Se2 Solar Cells by Formation of Ordered Vacancy Compound

In-situ X-ray diffraction annealing study of electroplated and sputtered Cu-In-Ga precursors for application to sequential Cu(In,Ga)Se2 processes

Two‐step selenization using nozzle free Se shower for Cu(In,Ga)Se2 thin film solar cell

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Product

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Tuning Ga Grading in Selenized Cu(In,Ga)Se₂ Solar Cells by Formation of Ordered Vacancy Compound

Tuning Ga Grading in Selenized Cu(In,Ga)Se₂ Solar Cells by Formation of Ordered Vacancy Compound

Two‐step selenization using nozzle free Se shower for Cu(In,Ga)Se₂ thin film solar cell