在我们以前的工作(Zhu C, Lü C Y, Gao Z F, Wang C X, Li D S, Ma X Y, Yang D R 2015 Appl.Phys.Lett.107 131103)中,利用掺铒(Er)二氧化钛薄膜(TiO2:Er)作为发光层,实现了基于ITO/TiO2:Er/SiO2/n+-Si结构的发光器件的Er相关可...在我们以前的工作(Zhu C, Lü C Y, Gao Z F, Wang C X, Li D S, Ma X Y, Yang D R 2015 Appl.Phys.Lett.107 131103)中,利用掺铒(Er)二氧化钛薄膜(TiO2:Er)作为发光层,实现了基于ITO/TiO2:Er/SiO2/n+-Si结构的发光器件的Er相关可见及近红外(约1540 nm)电致发光.本文将镱(Yb)共掺入TiO2:Er薄膜中,显著增强了Er相关可见及近红外电致发光.研究表明,一定量Yb的共掺会导致TiO2:Er薄膜由锐钛矿相转变为金红石相,从而使得Er3+离子周围晶体场的对称性降低.此外,Yb3+离子比Ti4+离子具有更大的半径,这使TiO2基体中Er3+离子周围的晶体场进一步畸变.晶体场的对称性降低及畸变使得Er3+离子4f能级间的跃迁概率增大.由于上述原因,Yb在TiO2:Er薄膜的共掺显著增强了相关发光器件的电致发光.展开更多
The effects of rapid thermal annealing(RTA)ambient on photoluminescence(PL)of sputtered ZnO films are investigated.The RTA at 800℃under either oxygen(O_(2))or argon(Ar)ambient can remarkably enhance the PL of the ZnO...The effects of rapid thermal annealing(RTA)ambient on photoluminescence(PL)of sputtered ZnO films are investigated.The RTA at 800℃under either oxygen(O_(2))or argon(Ar)ambient can remarkably enhance the PL of the ZnO films due to the improved crystallinities of the ZnO films.It is somewhat unexpected that the ZnO film which received the RTA under O_(2)ambient exhibits weaker near-band-edge(NBE)PL than that which received the RTA under Ar ambient.It is supposed that a certain amount of negatively charged oxygen species exist on the surface of the ZnO film that received the RTA under O_(2)ambient,leading to a build-in electric field.This in turn reduces the recombination probability of photo-generated electrons and holes,resulting in the suppressed NBE PL.展开更多
Hydrogen is omnipresent during the synthesis and processing of silicon nanocrystals (Si NCs).It is generally assumed that the incorporation of hydrogen leads to the passivation of Si dangling bonds at the NC surface.H...Hydrogen is omnipresent during the synthesis and processing of silicon nanocrystals (Si NCs).It is generally assumed that the incorporation of hydrogen leads to the passivation of Si dangling bonds at the NC surface.However,it is also speculated that hydrogen may be incorporated inside Si NCs.In this work the formation energy and probability of hydrogen in its three configurations,i.e.,hydrogen molecules,bond-centered atomic hydrogen,and antibonding atomic hydrogen,are calculated to rigorously evaluate the incorporation of hydrogen inside Si NCs.We find that hydrogen cannot be incorporated inside Si NCs with a diameter of a few nanometers at temperatures up to 1500K.展开更多
The behavior of wafers and solar cells from the border of a multicrystalline silicon(mc-Si)ingot,which contain deteriorated regions,is investigated.It is found that the diffusion length distribution of minority carrie...The behavior of wafers and solar cells from the border of a multicrystalline silicon(mc-Si)ingot,which contain deteriorated regions,is investigated.It is found that the diffusion length distribution of minority carriers in the cells is uniform,and high efficiency of the solar cells(about 16%)is achieved.It is considered that the quality of the deteriorated regions could be improved to be similar to that of adjacent regions.Moreover,it is indicated that during general solar cell fabrication,phosphorus gettering and hydrogen passivation could significantly improve the quality of deteriorated regions,while aluminum gettering by RTP could not.Therefore,it is suggested that the border of a me-Si ingot could be used to fabricate high efficiency solar cells,which will increase me-Si utilization effectively.展开更多
The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily p...The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily phosphorus-doped Czochralski(GHPCZ)silicon wafers is evaluated.It is suggested that both a good quality defect-free DZ with a suitable width in the sub-surface area and a high density bulk micro-defect(BMD)region could be formed in heavily phosphorus-doped Czochralski(HPCZ)silicon and GHPCZ silicon wafers.This is ascribed to the formation of phosphorus-vacancy(P-V)related complexes and germanium-vacancy(GeV)related complexes.Compared with HPCZ silicon,the DZ width is wider in the GHPCZ silicon sample with CFA-based denudation processing but narrower in the one with two-step RTA pretreatments.These phenomena are ascribed to the enhancing effect of germanium on oxygen out-diffusion movement and oxygen precipitate nucleation,respectively.Furthermore,fairly clean DZs near the surface remain in both the HPCZ and GHPCZ silicon wafers after Cu in-diffusion,except for the HPCZ silicon wafer which underwent denudation processing with a CFA pretreatment,suggesting that germanium doping could improve the gettering of Cu contamination.展开更多
文摘在我们以前的工作(Zhu C, Lü C Y, Gao Z F, Wang C X, Li D S, Ma X Y, Yang D R 2015 Appl.Phys.Lett.107 131103)中,利用掺铒(Er)二氧化钛薄膜(TiO2:Er)作为发光层,实现了基于ITO/TiO2:Er/SiO2/n+-Si结构的发光器件的Er相关可见及近红外(约1540 nm)电致发光.本文将镱(Yb)共掺入TiO2:Er薄膜中,显著增强了Er相关可见及近红外电致发光.研究表明,一定量Yb的共掺会导致TiO2:Er薄膜由锐钛矿相转变为金红石相,从而使得Er3+离子周围晶体场的对称性降低.此外,Yb3+离子比Ti4+离子具有更大的半径,这使TiO2基体中Er3+离子周围的晶体场进一步畸变.晶体场的对称性降低及畸变使得Er3+离子4f能级间的跃迁概率增大.由于上述原因,Yb在TiO2:Er薄膜的共掺显著增强了相关发光器件的电致发光.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61176042 and 60906024Zhejiang Provincial Natural Science Fund(No R4090055)+1 种基金the Innovation Team Project of Zhejiang Province(2009R50005)the Foundation of 2008DFR50250 of MOST.
文摘The effects of rapid thermal annealing(RTA)ambient on photoluminescence(PL)of sputtered ZnO films are investigated.The RTA at 800℃under either oxygen(O_(2))or argon(Ar)ambient can remarkably enhance the PL of the ZnO films due to the improved crystallinities of the ZnO films.It is somewhat unexpected that the ZnO film which received the RTA under O_(2)ambient exhibits weaker near-band-edge(NBE)PL than that which received the RTA under Ar ambient.It is supposed that a certain amount of negatively charged oxygen species exist on the surface of the ZnO film that received the RTA under O_(2)ambient,leading to a build-in electric field.This in turn reduces the recombination probability of photo-generated electrons and holes,resulting in the suppressed NBE PL.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50902122 and 50832006the R&D Program of Ministry of Education of China under Grant No 62501040202+2 种基金Basic Funding for Research at Zhejiang University under Grant No 2011FZA4005the Major Scientific Program of Zhejiang Province(2009C01024-2)Innovation Team Project of Zhejiang Province(2009R50005).
文摘Hydrogen is omnipresent during the synthesis and processing of silicon nanocrystals (Si NCs).It is generally assumed that the incorporation of hydrogen leads to the passivation of Si dangling bonds at the NC surface.However,it is also speculated that hydrogen may be incorporated inside Si NCs.In this work the formation energy and probability of hydrogen in its three configurations,i.e.,hydrogen molecules,bond-centered atomic hydrogen,and antibonding atomic hydrogen,are calculated to rigorously evaluate the incorporation of hydrogen inside Si NCs.We find that hydrogen cannot be incorporated inside Si NCs with a diameter of a few nanometers at temperatures up to 1500K.
基金Supported by the National Basic Research Program of China(973 Program)(No 2007CB613403)the Innovation Team Project of Zhejiang Province(2009R50005)the Fundamental Research Funds for the Central Universities,and Project of Science and Technology Department of Jiangxi Province.
文摘The behavior of wafers and solar cells from the border of a multicrystalline silicon(mc-Si)ingot,which contain deteriorated regions,is investigated.It is found that the diffusion length distribution of minority carriers in the cells is uniform,and high efficiency of the solar cells(about 16%)is achieved.It is considered that the quality of the deteriorated regions could be improved to be similar to that of adjacent regions.Moreover,it is indicated that during general solar cell fabrication,phosphorus gettering and hydrogen passivation could significantly improve the quality of deteriorated regions,while aluminum gettering by RTP could not.Therefore,it is suggested that the border of a me-Si ingot could be used to fabricate high efficiency solar cells,which will increase me-Si utilization effectively.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50832006 and 60906001the National Basic Research Program of China under Grant No 2007CB6130403,and the China Postdoctoral Science Foundation.
文摘The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily phosphorus-doped Czochralski(GHPCZ)silicon wafers is evaluated.It is suggested that both a good quality defect-free DZ with a suitable width in the sub-surface area and a high density bulk micro-defect(BMD)region could be formed in heavily phosphorus-doped Czochralski(HPCZ)silicon and GHPCZ silicon wafers.This is ascribed to the formation of phosphorus-vacancy(P-V)related complexes and germanium-vacancy(GeV)related complexes.Compared with HPCZ silicon,the DZ width is wider in the GHPCZ silicon sample with CFA-based denudation processing but narrower in the one with two-step RTA pretreatments.These phenomena are ascribed to the enhancing effect of germanium on oxygen out-diffusion movement and oxygen precipitate nucleation,respectively.Furthermore,fairly clean DZs near the surface remain in both the HPCZ and GHPCZ silicon wafers after Cu in-diffusion,except for the HPCZ silicon wafer which underwent denudation processing with a CFA pretreatment,suggesting that germanium doping could improve the gettering of Cu contamination.
