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Flexible thin film pH sensor based on low‐temperature atomic layer deposition
Author(s) -
Jakob Markus H.,
Gutsch Sebastian,
Chatelle Claire,
Krishnaraja Abinaya,
Fahlteich John,
Weber Wilfried,
Zacharias Margit
Publication year - 2017
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201700123
Subject(s) - polyethylene naphthalate , atomic layer deposition , materials science , thin film , layer (electronics) , silicon , deposition (geology) , fabrication , optoelectronics , silicon dioxide , analytical chemistry (journal) , zinc , nanotechnology , chemistry , composite material , metallurgy , environmental chemistry , medicine , paleontology , alternative medicine , pathology , sediment , biology
Flexible and transparent zinc oxide (ZnO) thin film field‐effect transistors (TF‐FET) for the use as small volume potentiometric pH sensors are developed. Low temperature atomic layer deposition (ALD) is used for the fabrication of the metal oxides ZnO and aluminum dioxide (Al 2 O 3 ). Changing the deposition temperature of the ZnO from 150 to 100 °C allowed a significant increase in resistivity by four orders of magnitude. Hence, adjusting the controlled low carrier concentration for the field‐effect based sensor is demonstrated. ZnO TF‐FET pH sensors fabricated on silicon/silicon dioxide (Si/SiO 2 ) substrates are compared with sensors based on flexible and transparent polyethylene naphthalate (PEN) foil substrates. Comparison of both types of pH sensors showed successful pH sensitivity for pH ranging from 5 to 10 in both cases.