The effect of Si （100） surface S passivation was investigated. A thick film with a high roughness value was formed on the Si surface treated by （NH4）2S solution, which was attributed to physical adsorption of S at...The effect of Si （100） surface S passivation was investigated. A thick film with a high roughness value was formed on the Si surface treated by （NH4）2S solution, which was attributed to physical adsorption of S atoms. SEM and XPS analyses reveal that Si surface atoms were chemically bonded with S atoms after Si surface treatment in NH4OH and （NH4）2S mixing solution. This induces a more ideal value for the Schottky barrier height compared with a diode treated only by HF solution, indicating that surface states originating from dangling bonds are passivated with S atoms.展开更多
The impact of nitridation and sulfur passivation for Ino.s3Gao.47As surfaces on the A1/A1203/InGaAs MOS capacitors properties was investigated by comparing the characteristics of frequency dispersion and hysteresis, c...The impact of nitridation and sulfur passivation for Ino.s3Gao.47As surfaces on the A1/A1203/InGaAs MOS capacitors properties was investigated by comparing the characteristics of frequency dispersion and hysteresis, calculating the Dit and ANbt values, and analyzing the interface traps and the leakage current. The results showed that both of the methods could form a passivation-layer on the InGaAs surface. The samples treated by N2 plasma could obtain good interface properties with the smallest frequency dispersion in the accumulation region, and the best hysteresis characteristics and good I-V properties were presented. Also the samples with （NH4）ESx treatment showed the smallest frequency dispersion near the flat-band region and a minimum Dit value of 2.6 x10^11 cm-2 eV-1.展开更多
The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorp...The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH_(3) and sulphate and explore the reaction behaviour of NH_(3) with SO_(2) and H_(2)SO_(4). On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH_(3), the decomposition of (NH_(4))_(2)SO_(4) and NH_(4)HSO_(4) are 224, 276 and 319 ℃, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH_(3) amount, only a small portion of H_(2)SO_(4) is converted to sulphate, as the H_(2)SO_(4) deposited in AC pores or agglomerated together could not come into contact with NH_(3). The final reaction product of NH_(3) and SO_(2) is mainly (NH_(4))_(2)SO_(4) which is continuously generated because the newly generated H_(2)SO_(4) is continually exposed to NH_(3), if NH_(3) is enough. The reaction of NH_(3) with H_(2)SO_(4) takes precedence over with NH_(4)HSO_(4). In the initial stages in which H_(2)SO_(4) is exposed to NH_(3), the product is essentially all NH_(4)HSO_(4) as intermediate. Then, it is further converted to (NH_(4))_(2)SO_(4) whose amount reaches equilibrium when the accessible H_(2)SO_(4) is exhausted. All the NH_(3) adsorbed on AC entering the desulphurisation tower generates NH_(4)HSO_(4), but the amount is limited. The remaining SO_(2) entering the denitrification tower mainly generates (NH_(4))_(2)SO_(4);thus, limiting the remaining SO_(2) amount is necessary to guarantee denitrification efficiency. When the NH_(3) injection is changed to the desulphurisation tower, the initial NH_(3) injection rate can be increased to complete the conversion of accessible H_(2)SO_(4) as soon as possible in order to obtain higher denitrification efficiency.展开更多
基金supported by the State Key Development Program for Basic Research of China(No.2006CB302704)
文摘The effect of Si （100） surface S passivation was investigated. A thick film with a high roughness value was formed on the Si surface treated by （NH4）2S solution, which was attributed to physical adsorption of S atoms. SEM and XPS analyses reveal that Si surface atoms were chemically bonded with S atoms after Si surface treatment in NH4OH and （NH4）2S mixing solution. This induces a more ideal value for the Schottky barrier height compared with a diode treated only by HF solution, indicating that surface states originating from dangling bonds are passivated with S atoms.
基金supported by the National Natural Science Foundation of China(Nos.61274077,61474031,61464003)the Guangxi Natural Science Foundation(Nos.2013GXNSFGA019003,2013GXNSFAA019335)+2 种基金the Project(No.9140C140101140C14069)the Innovation Project of GUET Graduate Education(No.YJCXS201529)the National Science&Technology Major Project of China(No.2011ZX02708-003)
文摘The impact of nitridation and sulfur passivation for Ino.s3Gao.47As surfaces on the A1/A1203/InGaAs MOS capacitors properties was investigated by comparing the characteristics of frequency dispersion and hysteresis, calculating the Dit and ANbt values, and analyzing the interface traps and the leakage current. The results showed that both of the methods could form a passivation-layer on the InGaAs surface. The samples treated by N2 plasma could obtain good interface properties with the smallest frequency dispersion in the accumulation region, and the best hysteresis characteristics and good I-V properties were presented. Also the samples with （NH4）ESx treatment showed the smallest frequency dispersion near the flat-band region and a minimum Dit value of 2.6 x10^11 cm-2 eV-1.
基金support of China Petrochemical Corporation Funding(Sinopec Group,No.321094).
文摘The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH_(3) and sulphate and explore the reaction behaviour of NH_(3) with SO_(2) and H_(2)SO_(4). On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH_(3), the decomposition of (NH_(4))_(2)SO_(4) and NH_(4)HSO_(4) are 224, 276 and 319 ℃, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH_(3) amount, only a small portion of H_(2)SO_(4) is converted to sulphate, as the H_(2)SO_(4) deposited in AC pores or agglomerated together could not come into contact with NH_(3). The final reaction product of NH_(3) and SO_(2) is mainly (NH_(4))_(2)SO_(4) which is continuously generated because the newly generated H_(2)SO_(4) is continually exposed to NH_(3), if NH_(3) is enough. The reaction of NH_(3) with H_(2)SO_(4) takes precedence over with NH_(4)HSO_(4). In the initial stages in which H_(2)SO_(4) is exposed to NH_(3), the product is essentially all NH_(4)HSO_(4) as intermediate. Then, it is further converted to (NH_(4))_(2)SO_(4) whose amount reaches equilibrium when the accessible H_(2)SO_(4) is exhausted. All the NH_(3) adsorbed on AC entering the desulphurisation tower generates NH_(4)HSO_(4), but the amount is limited. The remaining SO_(2) entering the denitrification tower mainly generates (NH_(4))_(2)SO_(4);thus, limiting the remaining SO_(2) amount is necessary to guarantee denitrification efficiency. When the NH_(3) injection is changed to the desulphurisation tower, the initial NH_(3) injection rate can be increased to complete the conversion of accessible H_(2)SO_(4) as soon as possible in order to obtain higher denitrification efficiency.
