New conductive materials include: two-dimensional materials, organic conductive materials, and silver nanowire materials.
1. Two-dimensional material
A two-dimensional material is a material with a thickness of only a few atomic layers and has good electrical conductivity. Such as graphene and molybdenum disulfide are typical two-dimensional materials. These materials not only have high electrical conductivity, but also have excellent properties such as high strength and high thermal conductivity. They are widely used in the manufacturing of electronic equipment, lithium-ion batteries and other fields.
2. Organic conductive materials
Organic conductive materials have developed rapidly in recent years, including polymers, carbon nanotubes, etc. These materials have the characteristics of mechanical softness, plasticity and high toughness, and are suitable for manufacturing foldable electronic devices, such as foldable and flexible displays, wearable devices, etc. Organic conductive materials are also widely used in solar cells, organic field effect transistors, etc.
3. Silver nanowire materials
Silver nanowire materials are conductive materials that have been further studied in recent years. They have high conductivity and flexibility and can create. flexible electronic devices such as flexible displays and curved batteries. Compared with traditional conductive materials, silver nanowire materials have higher conductivity and transparency and have a wider application range.
The origin of two-dimensional materials:
The full name of two-dimensional materials is two-dimensional atomic crystal materials. It was accompanied by the name. 2004 University of Manchester (University of Manchester) The Geim team successfully separated a single atomic layer of graphite material - graphene (graphene).
The outstanding characteristics of graphene are single-atom layer thickness, high carrier mobility, linear energy spectrum, and high resistance. Graphene has attracted great interest in both theoretical research and application fields. A.K. Geim himself called it the “gold rush”.
Subsequently, some other two-dimensional materials were separated, such as boron nitride (BN), molybdenum disulfide (MoS2), tungsten disulfide (WS2), and molybdenum diselenide ( MoSe2), tungsten diselenide (WSe2). ), MXene materials. Much research has recently been carried out in the field of physicsique of condensed matter.
Reference for the above content: Baidu Encyclopedia - Two-Dimensional Materials
Amorphous silicon (a-Si) solar cells are transparent and conductive deposited on a substrate of glass. film (TCO), then use plasma reaction to sequentially deposit three-layer a-Si of p-type, i-type and n-type, and then evaporate the aluminum from the metal electrode (Al). surface, and the battery current flows from the transparent conductive film and aluminum wires, and its structure can be expressed as glass/TCO/pin/Al, and stainless steel sheets, plastics, etc. can also be used as substrates.
Silicon is currently the dominant material for solar cells. Silicon represents almost 40% of the cost of finished solar cells. However, the thickness of amorphous silicon solar cells is less than 1 μm, which is less than 1 μm. lower thanthat of crystalline silicon solar cells 1/100 of the thickness, which significantly reduces the manufacturing cost, and because the manufacturing temperature of amorphous silicon solar cells is very low (~200 °C) and easy to make large areas, it is lower than that of crystalline silicon solar cells. occupies a primordial position in thin film solar cells. In terms of manufacturing methods, there are electron cyclotron resonance method, photochemical vapor deposition method, DC glow discharge method, radio frequency glow discharge method, sputtering method and hot wire method. . In particular, the radio frequency glow discharge method can easily achieve continuous production over large areas and large volumes due to its low temperature process (~200 °C), and has now become a technologye mature recognized internationally. In terms of materials research, a-SiC window layer, gradient interface layer, μC-SiC p layer, etc. were studied successively, which significantly improved the shortwave spectral response of the battery due to photogenerated generation. The carriers of a-Si solar cells are mainly in the i layer, the incident light is partially absorbed by the p layer before reaching the i layer, which is inefficient for power generation. The a-SiC and μC-SiC materials have a wider optical band. larger than p-type a-Si, thus reducing the impact on light. Absorption increases light reaching the i-layer, coupled with the use of gradient interface layers, the photoelectron transport characteristics at the a-SiC/a-Si heterojunction interface; are improved in terms of increasing the response to long waves, the filmss textured TCOs, the multilayer retroreflective electrode with textured surface (ZnO/Ag/Al) and the stacked structure with multiple band gaps, namely glass/TCO/p1i1n1/p2i2n2/p3i3n3/ZnO. Structure /Ag/Al. The textured TCO film and multi-layer rear reflective electrode reduce the light reflection and transmission loss and increase the light propagation distance in the i-layer, thereby increasing the light absorption in the i-layer. In the multiple bandgap structure, the bandgap width of layer i decreases sequentially from the light incident direction. In order to absorb sunlight in sections, the purpose of broadening the spectral response and improving the conversion efficiency is achieved. In terms of improving the efficiency of tandem cells, gradient band gap designs, microcrystalline doping layers in tunnel junctions, etc. are also usedes to improve the collection of carriers.
In order to obtain silicon-based thin-film solar cells with high efficiency and high stability, microcrystalline and polycrystalline silicon thin-film cells have appeared in recent years. Microcrystalline silicon films are prepared using high hydrogen dilution and boron doping techniques. There are two main polysilicon film manufacturing technologies: one is direct growth using PECVD technology or hot wire method; the other is to achieve low-temperature solid-phase crystallization by post-annealing of a-Si:H materials.