Synthesis of High Quality CulnSe2 Films with Oxygen Precursor by Non-vacuum Process

The CulnSe2 absorber was synthesized by non-vacuum process with a simple and low-cost method, which fabricated absorber layer of thin-film solar cell. The extra amount of Se was added into the ink to help reduction of the oxide and solid Se fountain was used to provide Se atmosphere during the selenization progress. The influence of same factors was investigated, such as the time of reduction in H2, the time of selenization and the Se vapor pressure. The selenizaion, processed at 550 ℃ for 60 min with the Se vapor pressure at 1.90 kPa, resulted in high quality CulnSe2 layer with very good chemical composition.

Cutting and Welding of High-Strength Steels Using Non-Vacuum Electron Beam as a Universal Tool for Material Processing

Using a non-vacuum electron beam, a two-step process chain for plate materials is a feasible possibility. Cutting and welding can be performed in subsequent steps on the same machine for a highly productive process chain. The electron beam is a tool with high energy conversion efficiency, which is largely independent of the type of metal. Its high power density qualifies the non-vacuum electron beam as an outstanding energy source for the well-known NVEB welding as well as for high-speed cutting. Welding is possible with or without filler wire or shielding gas, depending on the application. The NVEB-cutting process employs a co-moving cutting head with a sliding seal for extremely high cutting speeds producing high quality edges. Due to direct removal of fumes and dust, NVEBC with local suction is an exceptionally clean and fast process. The NVEB welding process is possible directly after cutting, without further edge preparation. The potential directions of development of non-vacuum electron beam technologies are discussed. An exemplary two-step process chain using high-strength steel is presented to highlight possible application in industries such as general steel construction, automotive, shipbuilding, railway vehicle or crane construction. An analysis of the mechanical properties of the resulting weld seam is presented.

Study on process of roll bonding stainless and carbon steel under non-vacuum condition

The non-vacuum roll bonding method of nickel plating on the base materials is put forward in accordance with the primary problems existed in the roll bonding of stainless/carbon steel. After nickel plating test on the base materials, the microstructure of nickel cladding is observed by scanning electron microscopy （SEM） at high, and room temperature, and the results show that the nickel cladding on base material can be protected from oxidation in the high temperature. Non-vacuum roll bonding tests of nickel plating on base materials are done by the roll bonding equipment, and the roll bonding plates of stainless/carbon steel are obtained. The microstructure and the elements distribution of non-vacuum roll bonding interface are analyzed by optical microscope （OM） and SEM. The results reflect that the nickel plating layer and the base materials bond well.

Doctor-bladed Cu_2ZnSnS_4 light absorption layer for low-cost solar cell application

The doctor-blade method is investigated for the preparation of Cu2ZnSnS4 films for low-cost solar cell application. Cu2ZnSnS4 precursor powder, the main raw material for the doctor-blade paste, is synthesized by a simple ball-milling process. The doctor-bladed Cu2ZnSnS4 films are annealed in N2 ambient under various conditions and characterized by X-ray diffraction, ultraviolent/vis spectrophotometry, scanning electron microscopy, and current-voltage （J-V） meansurement. Our experimental results indicate that （i） the X-ray diffraction peaks of the Cu2ZnSnS4 precursor powder each show a red shift of about 0.4°; （ii） the high-temperature annealing process can effectively improve the crystallinity of the doctor-bladed Cu2ZnSnS4, whereas an overlong annealing introduces defects; （iii） the band gap value of the doctor-bladed Cu2ZnSnS4 is around 1.41 eV; （iv） the short-circuit current density, the open-circuit voltage, the fill factor, and the efficiency of the best Cu2ZnSnS4 solar cell obtained with the superstrate structure of fluorine-doped tin oxide glass/TiO2/In2S3/Cu2ZnSnS4/Mo are 7.82 mA/cm2, 240 mV, 0.29, and 0.55%, respectively.