Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface ...Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface generation method are poor, because of the high surface recombination caused by deep etching in the conventional surface generation method for BS. In this work, a modified wet chemical etching solution with additives was developed. A homogeneous BS layer with random porous structure was obtained from the modified solution in only one step at room temperature. The BS layer had low reflectivity and shallow etching depth. The additive in the etch solution performs the function of pH-modulation. After 16-min etching, the etching depth in the samples was approximately 200 nm, and the spectrum-weighted-reflectivity in the range from 300 nm to 1200 nm was below 5%. BS solar cells were fabricated in the production line. The decreased etching depth can improve the electrical performance of solar cells because of the decrease in surface recombination. An efficiency of 15.63% for the modified etching BS solar cells was achieved on a large area, p- type single crystalline silicon substrate with a 624.32-mV open circuit voltage and a 77.88% fill factor.展开更多
FeCl_(3) solution is commonly used in the etching process of stainless steel.The typical etching waste liquid contains a significant amount of Fe^(3+),Fe^(2+),Cr^(3+),and Ni^(2+),making it difficult to reuse and posin...FeCl_(3) solution is commonly used in the etching process of stainless steel.The typical etching waste liquid contains a significant amount of Fe^(3+),Fe^(2+),Cr^(3+),and Ni^(2+),making it difficult to reuse and posing pollution issues.The FeCl_(3) etching waste liquid was the present subject,which aimed to extract Cr^(3+)and Ni^(2+)by selectively adjusting process parameters.Additionally,it investigates the migration behavior and phase transition mechanisms of the iron,chromium,and nickel in different solution systems during treatment,systematically elucidating the regeneration mechanisms of FeCl_(3) etching waste liquid.The results indicate that Cr and Ni can be recycled by controlling parameters such as pH value,temperature,and the valence states of the ions.Following a selective reduction of Fe^(3+)to Fe^(2+)using Fe powder,98.3%of Cr^(3+)was recovered by adjusting the solution’s pH.Subsequently,93.3%of Ni^(2+)was extracted from the Cr-depleted solution through further adjustments to the process parameters.The recovered Cr and Ni can be used to prepare Fe–Cr and Fe–Ni alloy powders.Furthermore,the FeCl_(3) etching solution was regenerated by oxidizing Fe^(2+)and recovering impurities.The theoretical support for the development of new processes for treating FeCl_(3) etching waste liquid is provided.展开更多
A novel wet etching method for AlGaN/GaN heterojunction structures is proposed using thermal oxidation f ollowed by wet etching in KOH solution.It is found that an AlGaN/GaN heterostructure after high temperature oxid...A novel wet etching method for AlGaN/GaN heterojunction structures is proposed using thermal oxidation f ollowed by wet etching in KOH solution.It is found that an AlGaN/GaN heterostructure after high temperature oxidation above 700℃could be etched off in a homothermal（70℃） KOH solution while the KOH solution had no etching effects on the region of the AlGaN/GaN heterostructure protected by a SiO_2 layer during the oxidation process.A groove structure with 150 nm step depth on an AlGaN/GaN heterostructure was formed after 8 h thermal oxidation at 900℃followed by 30 min treatment in 70℃KOH solution.As the oxidation time increases,the etching depth approaches saturation and the roughness of the etched surface becomes much better.The physical mechanism of this phenomenon is also discussed.展开更多
文摘Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface generation method are poor, because of the high surface recombination caused by deep etching in the conventional surface generation method for BS. In this work, a modified wet chemical etching solution with additives was developed. A homogeneous BS layer with random porous structure was obtained from the modified solution in only one step at room temperature. The BS layer had low reflectivity and shallow etching depth. The additive in the etch solution performs the function of pH-modulation. After 16-min etching, the etching depth in the samples was approximately 200 nm, and the spectrum-weighted-reflectivity in the range from 300 nm to 1200 nm was below 5%. BS solar cells were fabricated in the production line. The decreased etching depth can improve the electrical performance of solar cells because of the decrease in surface recombination. An efficiency of 15.63% for the modified etching BS solar cells was achieved on a large area, p- type single crystalline silicon substrate with a 624.32-mV open circuit voltage and a 77.88% fill factor.
基金financially supported by the National Natural Science Foundation of China(Nos.52074078 and 52374327)the Applied Fundamental Research Program of Liaoning Province(No.2023JH2/101600002)+5 种基金the Liaoning Provincial Natural Science Foundation of China(No.2022-YQ-09)the Shenyang Young Middle-Aged Scientific and Technological Innovation Talent Support Program,China(No.RC220491)the Liaoning Province Steel Industry-University-Research Innovation Alliance Cooperation Project of Bensteel Group,China(No.KJBLM202202)the Fundamental Research Funds for the Central Universities,China(Nos.N2201023 and N2325009)the Key Scientific Research Project of Liaoning Provincial Department of Education(2024JYTZD-03)the 111 Project(B16009).
文摘FeCl_(3) solution is commonly used in the etching process of stainless steel.The typical etching waste liquid contains a significant amount of Fe^(3+),Fe^(2+),Cr^(3+),and Ni^(2+),making it difficult to reuse and posing pollution issues.The FeCl_(3) etching waste liquid was the present subject,which aimed to extract Cr^(3+)and Ni^(2+)by selectively adjusting process parameters.Additionally,it investigates the migration behavior and phase transition mechanisms of the iron,chromium,and nickel in different solution systems during treatment,systematically elucidating the regeneration mechanisms of FeCl_(3) etching waste liquid.The results indicate that Cr and Ni can be recycled by controlling parameters such as pH value,temperature,and the valence states of the ions.Following a selective reduction of Fe^(3+)to Fe^(2+)using Fe powder,98.3%of Cr^(3+)was recovered by adjusting the solution’s pH.Subsequently,93.3%of Ni^(2+)was extracted from the Cr-depleted solution through further adjustments to the process parameters.The recovered Cr and Ni can be used to prepare Fe–Cr and Fe–Ni alloy powders.Furthermore,the FeCl_(3) etching solution was regenerated by oxidizing Fe^(2+)and recovering impurities.The theoretical support for the development of new processes for treating FeCl_(3) etching waste liquid is provided.
基金supported by the National Natural Science Foundation of China(Nos.60406004,60890193,60736033)the National Key Micrometer/Nanometer Processing Laboratory,China
文摘A novel wet etching method for AlGaN/GaN heterojunction structures is proposed using thermal oxidation f ollowed by wet etching in KOH solution.It is found that an AlGaN/GaN heterostructure after high temperature oxidation above 700℃could be etched off in a homothermal（70℃） KOH solution while the KOH solution had no etching effects on the region of the AlGaN/GaN heterostructure protected by a SiO_2 layer during the oxidation process.A groove structure with 150 nm step depth on an AlGaN/GaN heterostructure was formed after 8 h thermal oxidation at 900℃followed by 30 min treatment in 70℃KOH solution.As the oxidation time increases,the etching depth approaches saturation and the roughness of the etched surface becomes much better.The physical mechanism of this phenomenon is also discussed.
