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CEATEC 2021 ONLINE (October 19 - 22)


CEATEC 2021 ONLINE Perovskite solar cell will be practiced in the near future

October 19 - 22, CEATEC 2021 ONLINE were held by the online method. Main topics are closed up based on the official homepage (HP).


Picture 1. 120-inch 8K display
Sharp appeals 120-inch 8K display

Sharp appealed a 120-inch 8K display as ultra-high resolution display. It's useful for showroom, shopwindow, public viewing display, and office use. Contrast ratio was ultimately increased by setting 2048 units of direct LED backlights. By the way, full HD and 4K image can be up-converted into 8K grade image.

Toshiba introduces film-based perovskite solar cell

Toshiba appealed a film-based perovskite solar cell for next-generation solar power generation. It's possible to set curved plane and roof with low load, which is difficult to set in the past, because of thin type and low weight. In fact, power conversion efficiency (PCE) of this device is 15.1%, which is almost same as that of the conventional polycrystal Si solar cell. Its practical realization became to be near future.


Picture 2. Film-based perovskite solar cell


Figure 1. Image of meniscus coating
The company succeeded to develop an original coating technology (the meniscus coating method) of perovskite (PVK) layer. Figure 1 shows its process. It's possible to uniformly coat PVK ink on a large substrate by making use of surface tension of ink.

In the past, the company coated PbI ink, and dried, the next, coated MAI ink, and dried. In short, crystal MAPbI3 was obtained by 2 step process. In this time, 1 step process was developed. Concretely prepared MAPbI3 in advance is coated with control of crystal growth by the meniscus method.

The company previously developed a two-step coating process that first applied a layer of PbI2 (lead iodide) ink to a substrate, followed by a layer of MAI (methyammonium iodide, CH3NH3I) ink, triggering a reaction that formed an MAPbI3 layer. However, this multi-step approach had a low coating rate and often left unreacted sections in PVK layer. The alternative is a one-step process that applies MAPbI3 ink directly, but it is not easy to control crystallization of the MAPbI3 and obtain a uniform PVK layer across a large area. A new coating method that solves these problems was required.

The company developed a one-step meniscus coating method that uses improved ink, film drying processes and production equipment to form a uniform PVK layer over an area as large as 703cm2. These innovations halve the steps for deposition of PVK layer, and raise the coating speed to 6m/min on a 5×5 cm2 module, a rate that meets requirements for mass production.

The innovative coating method for PVK layer also greatly reduces production time and costs, contributing to a lower cost for solar power generation.

Sumitomo Bakelite developed electrochromic modulated light sheet

As concerns material, Sumitomo Bakelite introduced an electrochromic modulated light sheet for E-paper display.

Electrochromic (EC) phenomenon indicates that color of film is changed reversibly by electrochemical redox reaction. ECD has wide view angle property and memory property, so that, it is useful for E-paper display.

In the past, EC ink was supplied as primary material, on the other hand, the company succeeded to develop sheet type. Its writing speed is fast same as 5 - 10sec, and also, transmittance is high. Furthermore, color and transmittance can be controlled, too.

For this reason, it can be adopted to eye-wear products (sunglasses, smart glasses), electric mirror of automobile, and so on.

REMARK
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