![[지금은 과학] Even making electricity and being transparent… Next-generation solar cell came out](http://img.lb.inews24.com/facebookexternalhit/face/626x352/image_gisa/202102/1612405285377_1_112136.jpg "[지금은 과학] Even making electricity and being transparent… Next-generation solar cell came out")
[아이뉴스24 정종오 기자] A next-generation transparent solar cell was developed.
In addition to electricity generation, transparency is guaranteed, and it is expected that it will be able to preoccupy the next-generation solar market such as building exterior walls and windows, urban structures, mobility, and devices.
Efforts to expand renewable energy are accelerating as a key task in promoting energy conversion and the Green New Deal to realize a carbon neutral society in 2050. In the midst of this, a domestic research team developed a future energy harvesting solar cell technology that can be applied to the next-generation high value-added solar field.
Energy harvesting refers to a technology that harvests or scavenges natural energy such as sunlight, wind, water, vibration, and temperature, or energy discarded in daily life, into electrical energy.
Korea Institute of Energy Research (CEO Kim Jong-nam) released a core technology of high-efficiency CIGS double-sided light-transmitting solar cells that can simultaneously secure visual light transmittance by transmitting a part of sunlight along with electricity generation. Through the development technology, the power generation efficiency of 10% or more of visible light transmittance has secured performance of more than 10% on one side and 15% on both sides.
CIGS thin-film solar cell is a next-generation solar cell that uses Cu(In,Ga)Se2 inorganic compound composed of four elements of copper, indium, gallium, and selenium as a light absorbing layer, and is a future technology that is the most advanced commercialization after silicon solar cell.
◆Because it is transparent, it can be used everywhere
Transparent solar cells are expected to be applied as various energy harvesting cells such as building exterior walls and windows, city structures, mobility, devices, etc., as they can realize electricity generation and visible light transmission together. The development of solar cell technology with efficiency, light transmittance, durability, and low-light power generation performance has not been made yet.
Transparent solar cells, which are partially commercialized, are manufactured by scraping or punching some of the previously developed solar cells. For this reason, there is a drawback of causing visual discomfort due to the intersection of transparent and opaque parts with low performance and high production cost.
A transparent solar cell using an organic or organic-inorganic compound light absorbing layer has a disadvantage in that its performance is greatly degraded in a short time in a long period of light irradiation or a high temperature and humidity environment.
To solve this problem, Joon-Sik Jo (corresponding author) of the Solar Research Group, a researcher at the Photovoltaic Research Group, has made indium tin on both sides of the CIGS light absorbing layer, which is an inorganic material with excellent durability in light irradiation and temperature and humidity, unlike conventional molybdenum (Mo) metal electrodes. An oxide (Sn-doped indium oxide; ITO) transparent electrode was used.
It has developed a double-sided power generation transparent solar cell technology that allows self-transmission by precisely controlling the thickness of the light absorbing layer to less than 0.3 micrometers that can transmit part of the incident visible light.
This technology uses a simple and highly reproducible single-stage co-evaporation process instead of the complex 3-stage co-evaporation process used in the existing CIGS solar cell manufacturing, reducing the deposition time by half.
The thickness of the light absorbing layer has been reduced from 2 micrometers to less than 0.3 micrometers, significantly reducing material usage and processing time to a tenth level compared to the existing process.
A device structure using a thin light absorbing layer through which visible light can be transmitted and a double-sided transparent electrode can secure natural light transmittance, thereby increasing production yield and significantly lowering manufacturing cost compared to existing technologies.
Ji-Hye Kwak, head of the Renewable Energy Research Institute of Korea Institute of Energy Research, said, “The developed technology can develop into a solar cell super-gap technology that can overcome the performance and application limitations of existing commercial solar cell technologies by using differentiated new device structures and processes.” It is expected that the expansion of solar power supply through the discovery of various solar application fields will contribute to the realization of the carbon neutrality and Green New Deal policies that the government is promoting.
The research results (thesis title: Semitransparent and bifacial ultrathin Cu(In,Ga)Se2 solar cells via a single-stage process and light-management strategy) were published in Nano Energy, an international journal in the field of materials science.
The lead author is Shin Min-jung, a researcher at the Korea Institute of Energy Research and Solar Energy Research Group. Co-authors are Areum Lee, Researchers at Solar Research Center, Ara Jo, Kihwan Kim, Seunggyu Ahn, Jinsoo Park, Jinsoo Yoo, Jaeho Yoon, Donghyup Shin, Inyoung Jung, and Jihye Kwak, Director of Renewable Energy Research Institute.
Sejong = Reporter Jeong Jong-oh [email protected]