Semiconductor device manufacturing: process – Chemical etching – Altering etchability of substrate region by compositional or...
Reexamination Certificate
2005-10-04
2005-10-04
Norton, Nadine G. (Department: 1765)
Semiconductor device manufacturing: process
Chemical etching
Altering etchability of substrate region by compositional or...
C438S718000, C438S745000, C438S752000, C438S753000
Reexamination Certificate
active
06951819
ABSTRACT:
In one embodiment, a method of forming a multijunction solar cell having lattice mismatched layers and lattice-matched layers comprises growing a top subcell having a first band gap over a growth semiconductor substrate. A middle subcell having a second band gap is grown over the top subcell, and a lower subcell having a third band gap is grown over the middle subcell. The lower subcell is substantially lattice-mismatched with respect to the growth semiconductor substrate. The first band gap of the top subcell is larger than the second band gap of the middle subcell. The second band gap of the middle subcell is larger than the third band gap of the lower subcell. A support substrate is formed over the lower subcell, and the growth semiconductor substrate is removed. In various embodiments, the multijunction solar cell may further comprise additional lower subcells. A parting layer may also be provided between the growth substrate and the top subcell in certain embodiments. Embodiments of this reverse process permit the top and middle subcells to have high performance by having atomic lattice spacing closely matched to that of the growth substrate. Lower subcells can be included with appropriate band gap, but with lattice spacing mismatched to the other subcells. The reduced performance caused by strain resulting from mismatch can be mitigated without reducing the performance of the upper subcells.
REFERENCES:
patent: 3907595 (1975-09-01), Lindmayer
patent: 6252287 (2001-06-01), Kurtz et al.
patent: 6278054 (2001-08-01), Ho et al.
patent: 6316715 (2001-11-01), King et al.
patent: 6340788 (2002-01-01), King et al.
patent: 6482672 (2002-11-01), Hoffman et al.
patent: 6534797 (2003-03-01), Edmond et al.
patent: 6670544 (2003-12-01), Kibbel et al.
patent: 6743974 (2004-06-01), Wada et al.
patent: 6765238 (2004-07-01), Chang et al.
patent: 2001/0018924 (2001-09-01), Hisamatsu et al.
patent: 2002/0117675 (2002-08-01), Mascarenhas
Venkatasubramanian, et al.,An Inverted-Growth Approach to Development of an IR-Transparent, High-Efficiency AJGaAs/GaAs Cascade Solar Cell, Conference Record of the 22ndIEEE Photovoltaic Specialists Conference, 1991, pp. 93-98.
Zahler, et al.,Wafer Bonding and Layer Transfer Processes for 4-Junction High Efficiency Solar Cells,In: Conference Record of the 29thIEEE Photovoltaic Specialists Conference, IEEE, New York, May 19-24, 2002, pp. 1039-1042.
Ho Frank F.
Iles Peter A.
Yeh Yea-Chuan M.
Blue Photonics Inc.
Knobbe Martens Olson & Bear LLP
Norton Nadine G.
Tran Binh X.
LandOfFree
High efficiency, monolithic multijunction solar cells... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High efficiency, monolithic multijunction solar cells..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High efficiency, monolithic multijunction solar cells... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3449166