In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p...In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p+-emitters are formed by boron diffusion in an open-tube furnace using borontribromide（BBr3） as precursor. The formed emitters are characterized in detail in terms of shape of the doping profile, surface doping concentration, junction depth, sheet resistance and removal of the boron-rich layer（BRL）. In the aspect of BRL removal, three different methods were adopted to investigate their influence on device performance. The results demonstrate that our proposed chemical etch treatment（CET） with the proper etching time could be an effective way to remove the BRL.After removal of the BRL, Al;O;/SiN;stacks are deposited by atomic layer deposition（ALD） and plasma-enhanced chemical vapor deposition（PECVD） to passivate the cell surface. It was found that a reasonably-high implied Voc of 680 mV has been achieved for the fabricated n-type Si solar cells.展开更多
The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We an...The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well （IQW） model with strain, in the framework of the 6 × 6 k.p Hamiltonian for the valence states, to directly assess the interplay between the spin-orbit coupling and the strain-induced deformation potential for the interband momentum-matrix element. We numerically addressed problems of both the infinite and IQWs with piezoelectric fields to elucidate the effects of the piezoelectric potential and the deformation potential on the straindependent luminescence. The experimentally measured photoluminescence variation as a function of pressure can be qualitatively explained by the theoretical results.展开更多
基金Project supported by the Beijing Municipal Science and Technology Commission,China(No.Z151100003515003)the Beijing Natural Science Foundation(No.4173077,2184112)+3 种基金the Fundamental Research Funds for the Central Universities,China(Nos.FRF-BR-16-018A,FRF-TP-17-022A1,06400071)the National Natural Science Foundation of China(Nos.110751402347,61274134,51402064,61274059,51602340)the Beijing Municipal Innovation and Research Base,China(No.Z161100005016095)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2015387)
文摘In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p+-emitters are formed by boron diffusion in an open-tube furnace using borontribromide（BBr3） as precursor. The formed emitters are characterized in detail in terms of shape of the doping profile, surface doping concentration, junction depth, sheet resistance and removal of the boron-rich layer（BRL）. In the aspect of BRL removal, three different methods were adopted to investigate their influence on device performance. The results demonstrate that our proposed chemical etch treatment（CET） with the proper etching time could be an effective way to remove the BRL.After removal of the BRL, Al;O;/SiN;stacks are deposited by atomic layer deposition（ALD） and plasma-enhanced chemical vapor deposition（PECVD） to passivate the cell surface. It was found that a reasonably-high implied Voc of 680 mV has been achieved for the fabricated n-type Si solar cells.
基金Acknowledgements This work was supported by National Natural Science Foundation of China （Nos. 51472056 and 51402064）, the ＂thousands talents＂ program for pioneer researcher and his innovation team, China, the Recruitment Program of Global Youth Experts, China and Youth Innovation Promotion Assodation of Chinese Academy of Sciences （No. 2015387）. M. W. acknowledges financial support from the Chinese Academy of Sciences and the Beijing Institute for Nanoenergy and Nanosystems.
文摘The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well （IQW） model with strain, in the framework of the 6 × 6 k.p Hamiltonian for the valence states, to directly assess the interplay between the spin-orbit coupling and the strain-induced deformation potential for the interband momentum-matrix element. We numerically addressed problems of both the infinite and IQWs with piezoelectric fields to elucidate the effects of the piezoelectric potential and the deformation potential on the straindependent luminescence. The experimentally measured photoluminescence variation as a function of pressure can be qualitatively explained by the theoretical results.
