Conduction-type conversion in Ni(OH)₂ by intercalation of eosin Y

Nickel hydroxide (Ni(OH)₂) is one of the wide bandgap semiconductors. By controlling its conduction type, Ni(OH)₂ could be used as a semiconductor material in various applications. Since Ni(OH)₂ is a layered material, anions are intercalated into the interlayer spaces. Anion intercalation can be a potential impurity doping technique for Ni(OH)₂ films. In this study, we investigated the conduction type of Ni(OH)₂ intercalated with eosin Y. Ni(OH)₂ films formed by electrochemical deposition were n-type. After the intercalation of eosin Y, the Ni(OH)₂ films showed a p-type photocurrent response in photoelectrochemical measurements. The conduction type of the films was changed from n-type to p-type by the intercalation of eosin Y. In addition, the p-type Ni(OH)₂ films were used to form heterojunctions. The n-type ZnO/p-type Ni(OH)₂ heterojunction diode exhibited a rectifying behavior.