2013 Fiscal Year Final Research Report
Photovoltaic effects and photocarrier dynamics driven by depolarization field in ferroelectric semiconductors
| Project/Area Number |
24740202
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Condensed matter physics I
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2012-04-01 – 2014-03-31
|
| Keywords | 強誘電体 / 光起電力 / 時間分解分光 / 光電流 |
|---|
| Research Abstract |
Ferroelectric materials possess macroscopic polarization without external field. The spontaneous polarization in ferroelectrics causes bulk-photovoltaic effects: charge separation of photoexcited carriers occurs due to depolarization field, which results in photovoltage along the spontaneous polarization. In this study, the photocarrier recombination and relaxation dynamics in ferroelectric semiconductor BiFeO3 thin films by means of time-resolved transient absorption and photocurrent spectroscopy. This study revealed that photocarriers are trapped into shallow impurity state and the trapped carriers have long lifetimes. The long-lived carriers are related to the large photovoltage in BiFeO3 thin films.
|
