Solar / Thermal Energy Technology Technology Offers

Yissum - Research Development Company of the Hebrew University posted this:

Pre-filing Nov. 2016 Project ID : 9-2016-4371

Korea Institute of Energy Research posted this:

Researchers at the Korea Institute of Energy Research (KIER) have developed a method of fabricating copper indium gallium selenide (CIGS) thin film for solar cell. This innovative technology relates to a method of fabricating a copper indium gallium selenide (CIGS) thin film for solar cells through co-vacuum evaporation, and a CIGS thin film for solar cells fabricated using the same method. This advanced method enables the fabrication of CIGS thin-film using a simplified process of co-vacuum evaporation. Using this method enables an elimination of commonly experienced deterioration in the properties of thin-film crystal growth while encouraging improved band-gap gradings and sustaining reduced production costs. Solar cells are instrumental in climate change mitigation and adaption due to their capability for cheap mass production and minimal pollutant by-products. A key component in solar cell production is the use of a semiconductor material for solar energy absorption. CIGS, a semiconductor material, possess higher conversion than other thick film solar cell materials and, due to its capability to be fabricated to a thickness of 10 micros or less, can be stably operated even after long-term use. What’s more, CIGS is predicted to be a low-cost, high-efficiency solar material alternative to silicon. Solar cells can be divided into numerous types depending on the materials used in their light-absorption layer. The most commonly available solar cells are silicon solar cells, unfortunately due to the high cost of pure silicon these cells are becomingly less economically viable for mass production. Thin film type solar cells are fabricated to a thin thickness and thus require less material consumption, as well as being lightweight and having an increase in application range. A CIGS thin-film can be fabricated by vacuum deposition or non-vacuum coating. Particularly, vacuum deposition may include co-evaporation, in-line evaporation, a two-step process (precursor-reaction), and the like. Co-evaporation has traditionally been used to fabricate high-efficiency CIGS thin-film solar cells. However, co-evaporation technology is difficult to commercialisation due to the complicated nature of the process involved and the challenge of fabricating a large area solar cell. A partial solution to these issues has been the design of two-step (deposition/selenization) processes capable of facilitating mass production. However, these newly designed process often encounters drawbacks relating to scaling-up of technology and regulation of the flux of elements in each production step. Subsequently, there is a need for a simplified process of fabricating CIGS thin-film for solar cells which can achieve high crystal growth and improved band-gap grading. The technology, developed and presented by the KIER, has been conceived to solve the problems related to CIGS fabrication. This advanced technology offers a refined method of fabricating copper indium gallium selenide (CIGS) thin film for solar cells, using a streamlined co-vacuum evaporation process capable of maintaining crystal growth and band gas grading while also minimising production time and cost, as compared with conventional co-vacuum evaporation processes.

Korea Institute of Energy Research posted this:

Researchers at the Korea Institute of Energy Research (KIER) have developed a method of manufacturing high-density CIS thin film for solar cells. This innovative technology relates to a method of manufacturing high-density CIS thin film for solar cell and a method of manufacturing a thin film solar cell using the CIS thin film. Specifically, this technology relates to a method of manufacturing CIS thin-film by coating CIS, CIGS or CZTS nano-powders on a substrate via non-vacuum coating, followed by heat treatment with the cavities between the nano-powders being filled with elements such as copper, indium, gallium, zinc, tin, etc. Solar cells directly converting sunlight into electric energy have various merits such as avoidance of contamination, infinite resource and semi-permanent lifespan, and are thus anticipated as an energy source capable of solving the problem of energy depletion. A key component in solar cell production is the use of a semiconductor material for solar energy absorption. A CIS or GCIS thin film is a compound semiconductor which possesses a higher conversion efficiency, of about 19.9%, than other thin film solar cells and, due to its capability to be fabricated to a thickness of 10 micros or less, can be stably operated even after long-term use. What’s more, CIS or GCIS is anticipated as an inexpensive, highly efficient solar cell capable of replacing silicon. Solar cells are classified into five types depending on materials for a photo-absorption layer, and a silicon solar cell is most widely used in the art. Recently, however, a rapid increase in raw material costs due to undersupply of silicon has led to increasing interest in thin film solar cells. Thin film solar cells are manufactured to a low thickness, thereby providing merits such as low consumption of material, lightweight, wide application ranges, and the like. A GCIS solar cell is formed using a thin film having a thickness of several micrometres by vacuum deposition, or by precursor deposition in a non-vacuum state and heat treatment of the precursor-deposited thin film. Vacuum deposition is advantageous in that it provides a highly efficient absorption layer. However, vacuum deposition disadvantageously provides low uniformity and requires expensive equipment in forming a large area absorption layer, and causes a material loss of about 20% to 50%, which leads to high manufacturing costs. The inventors of the present invention carried out extensive studies to obtain a method of manufacturing a high-density CIS thin film, CIGS thin film or CZTS thin film through the non-vacuum coating. Subsequently identifying that high-density CIS thin film can be formed when heat treating the CIS thin film, CIGS thin film, CZTS thin film, with cavities of the film filled with filling elements such as copper, indium, gallium, zinc, tin, and the like. The technology, developed and presented by the KIER, has been conceived to solve the problems related to CIS fabrication for solar cells. This advanced technology offers a refined method for manufacturing high-density CIS thin film for solar cell and method of manufacturing thin film solar cell using the same, through a streamlined method which provides high-density CIS thin film while also minimising manufacturing costs and time requirements.

Korea Institute of Energy Research posted this:

Researchers at the Korea Institute of Energy Research (KIER) have developed an innovative device for controlling sample temperature during photoelectric and solar cell measurement. This technology specifically relates to a device for maintaining a constant temperature of solar cell samples in a procedure for measuring photoelectric and solar cell characteristic. This advanced technology is particularly valuable in response to the increasing attention being placed on alternative next-generation clean energy sources. As such, greater scientific research focus is being paid to fossil fuel alternatives, such as solar cells. Solar cells directly converting sunlight into electric energy have various merits such as avoidance of contamination, infinite resource and semi-permanent lifespan, and are thus anticipated as an energy source capable of solving the problem of energy depletion. Solar cells are semiconductor devices for solar energy generation. Performance indicators determine the value of a solar cell, for example; spectral responsibility, open circuit voltage, short circuit voltage, short circuit current, conversion efficiency and maximum output. These performance indicators are determined by measuring photoelectric characteristics using a test called Standard Test Condition (STC). For common crystalline silicon solar cells, which have relatively good thermal conductivity, and thin film solar cell, the indirect method of controlling sample temperature is fully efficient to due effective heat exchange between a sample stage and a sample. However, in the case of a thin film solar cell using a thick glass substrate or a solar cell that has an additional jig for measurement, the heat exchange between a sample stage and a sample is not effective. The inefficiencies experienced when measuring solar cell properties, of some solar cells, arise due to the difficulty encountered when attempting to maintain the temperature of the measurement target solar cell at values similar to those prescribed by STC conditions. Also, in the case of a dye-sensitized solar cell, which requires a relatively long time for measurement, the cell must be exposed to light for a prolonged period, making temperature measurements difficult to attain as well as suffering issues because of prolonged photo-irradiation. The technology, developed and presented by the KIER, has been conceived to solve the problems related to controlling sample temperatures during photoelectric and solar cell measurements. This advanced technology offers a refined, indirect, method for controlling sample temperatures, and may be used for measuring various photoelectric and solar cell characteristics.

Korea Institute of Energy Research posted this:

Researchers at the Korea Institute of Energy Research have developed a new method of managing the inherent limitations of heat pumps, in terms of their application for unpredictable heat energy sources. Heat pumps are devices that can produce hot water with a high temperature using a heat source with a low temperature. In general, heat pumps produce hot water with a set temperature and a set flow rate using a heat source that is introduced with both predetermined temperature and flow rate. However, with the increased use of new renewable heat sources, such as geothermal heat, sewage heat and solar heat; there is a need for heat pumps with the capacity to manage heat sources with characteristically unpredictable temperatures and flow rates that are prone to sudden change. What’s more, there is an increasing requirement for heat pumps capable of supplying hot water at varying temperatures, as opposed to one set temperature – to accommodate demand requirements. Conventional heat pumps are limited in their capability to sufficiently align the characteristics of heat sources and the characteristics of the demand source. Generally, demand sources for heat pump energy require both consistent temperatures and flow rates. Meaning that heat sources, such as renewables, which suffer unreliable temperatures and flow rates are generally unsuitable for heat pump use. The innovative broadband heat pump technology presented offers a unique system which can overcome the inherent limitations of heat pump technology. This technology enables the control of heat source temperatures in order that heat supplied is at a uniform temperature and can be tailored to meet the requirements of the demand source. This broadband heat pump technology has several beneficial implications. Notably the pump is capable of being supplied with hot water with various levels of temperature, which can then be supplied to any desired demand source. Additionally, since heat sources with varying levels of temperature, notably including renewable energy sources, can be used, energy availability increases, and the pump offers a gateway for renewable energy use.