A NOVEL DESCRIPTION OF ISFET SENSITIVITY WITH THE BUFFER CAPACITY AND DOUBLE-LAYER CAPACITANCE AS KEY PARAMETERS
A NOVEL DESCRIPTION OF ISFET SENSITIVITY WITH THE BUFFER CAPACITY AND DOUBLE-LAYER CAPACITANCE AS KEY PARAMETERS
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DOI：
10.1016/0925-4005(95)85043-0
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发表时间：
1995-03-01
影响因子：
8.4
通讯作者：
BERGVELD, P
中科院分区：
文献类型：
--
作者：
VANHAL, REG;EIJKEL, JCT;BERGVELD, P
ISFET的pH敏感性源于质子与ISFET栅极表面位置的相互作用。这种灵敏度可以用一个新的更简单的模型来描述，该模型以本征缓冲容量和差动电容为关键参数。所得表达式与用于化学表面平衡的模型和溶液中的电荷分布无关。利用结合位点理论和古伊-查普曼-斯特恩理论，给出了灵敏度的一般表达式。用这一理论解释了Ta2O5 ISFET具有较高灵敏度的原因。结果表明，电解液浓度对Ta2O5 ISFET的灵敏度几乎没有影响。
The pH sensitivity of ISFETs arises from interactions of protons with ISFET gate surface sites. This sensitivity is described by a new simpler model with the intrinsic buffer capacity and the differential, capacitance as key parameters. The obtained expression is independent of the models used for the chemical surface equilibria and the charge profile in the solution. The general expression for the sensitivity is elaborated using the site-binding theory and the Gouy-Chapman-Stern theory. The relatively high sensitivity of Ta2O5 ISFETs is explained using this elaborated theory. It is shown that the electrolyte concentration has almost no influence on the sensitivity of Ta2O5 ISFETs.