2006 Fiscal Year Final Research Report Summary
Development of Luminescence Technique for Accurate Diagnostic Characterization of Semiconductor Materials for Solar Cells
| Project/Area Number |
16206002
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied materials science/Crystal engineering
|
|---|
| Research Institution | Japan Aerospace Exploration Agency |
|---|
Principal Investigator |
TAJIMA Michio Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Professor (30216965)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IMAIZUMI Mitsuru Japan Aerospace Exploration Agency, Institute of Aerospace Technology, Associate Senior Engineer (90421859)
OHSHIMA Takeshi Japan Atomic Energy Agency, Quantum Beam Science Directorate, Senior Scientist (50354949)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Keywords | luminescence / solar cell / characterization / radiation effect |
|---|
| Research Abstract |
We have developed advanced techniques of photoluminescence (PL) and electroluminescence (EL) spectroscopy and their topography for an accurate diagnostic characterization of Si, InGaP_2/GaAs/Ge multi-junction (MJ) and Cu(In,Ga)Se_2 (CIGS) solar cells. PL is applicable to wafers without a cell structure, where the selective tuning of the excitation light is used to evaluate respective layers of multi-layered structures. The intensity of band-edge emission reflects the crystalline quality, since the intensity is proportional to the minority carrier lifetime. Analysis of deep-level emission enables us to identify the origin of the defects. Luminescence topography is useful to investigate the uniformity of the cells as well as the distribution of defects within them. PL and EL imaging with a highly sensitive CCD camera are particularly powerful for rapid and wide-area inspection of the cells. We have invented an ultra high-speed characterization technique for crystalline quality of multicrystalline Si (mc-Si) wafers which have 60% market share of solar cells. Images of band-edge emission from mc-Si wafers were taken by a cooled CCD camera within l s with the wafers immersed in a HF solution and excited by light-emitting-diode arrays. The present imaging technique is about ten thousand times faster and ten times higher in spatial resolution than conventional electrical characterization methods. We have demonstrated that the luminescence technique has great advantages of high sensitivity, high spatial resolution, high speed, noncontact and nondestructiveness, and that the technique is a powerful tool for characterizing semiconductor materials for solar cells.
|
Research Products
(52 results)
