2007 Fiscal Year Final Research Report Summary
Surface Passivation for High Efficiency Crystalline Silicon Solar Cells
| Project/Area Number |
18560810
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Energy engineering
|
|---|
| Research Institution | Tokyo University of Agriculture and Technology |
|---|
Principal Investigator |
KAMISAKO Koichi Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Associate Professor (40092481)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Keywords | crystalline silicon solar cell / silicon nitride film / amorphous silicon thin film / passivation / effective lifetime / thermal annealing |
|---|
| Research Abstract |
To investigate the passivation effects for high efficiency crystalline silicon solar cells, single layers or double layers of silicon nitride (SiNx : H) film and amorphous silicon (a-Si : H) film were deposited on mono-crystalline and multi-crystalline silicon substrates. The effective carrier lifetime and the thermal annealing effect were evaluated. The following results were obtained.
1. Passivation effects of SiNx : H films : Si rich films showed larger improvement of effective lifetime than N rich films.
2. Thermal annealing effect for the effective lifetime : The effective lifetimes in SiNx : H films were largely changed by temperature and duration of thermal annealing. From the results of FTIR, it was confirmed that the densities of Si-H and N-H bonds are changed by H atoms migration and this behavior is related to the passivation effect.
3. Passivation effects of SiNx : H/ SiNx : H double layers : By combination of SiNx : H films with different refractive indices, the effective lifetimes were more improved. Also it is possible to control the surface reflective property.
4. Passivation effects of SiNx : H/ a-Si : H double layers: SiNx : H/ a-Si : H double layers were deposited at low temperature of 250C. These layers were found to show extremely high improvement effect for the effective carrier lifetimes. Moreover the effective lifetimes were increased by thermal annealing.
5. Passivation effects of a-Si:H single layers: In a-Si:H single layers deposited at 250 C, the effective lifetimes were extremely improved by thermal annealing at 400-500 C.
6. Evaluation of passivation films for solar cells : The solar cells were actually made in our laboratory. The effects of SiNx : H film on the surface of the cell and a-Si : H film on the BSF layer of the cell were evaluated. As a result, improvement effects for conversion efficiency were verified.
|
Research Products
(28 results)
