A calculated value of 42% should be compared to calculated values for other solar cells (e.g., for a single junction solar cell, the theoretical limit is ~32%, multijunctions are higher, it could be > 42%, depending on how many junctions you want to have). The 15-20% is industrial level for single junction cells, it is much higher in the lab (e.g., > 40% for a triple-junction solar cell). The current level of the quantum dot cell is ~ 1% in the lab.
The four major PV technologies are in fact
1. Si
2. CdTe thin film
3. CIGS thin film
4. III-V multijunction
One could do concentrating PV for 1 and 4.
TiO2 dye sensitized solar cell has around 10% lab efficiency and low cost, but generally unstable, thus, not in production. One of the nanowire solar cells is a proposal to improve such solar cell by replacing dye with a semiconductor shell.
Quantum Dots (Which allow for up to 7 electrons to be created from 1 photon): not even reaching 1 % efficiency so far (anything can get that efficiency). Buy 1 get 6 free sounds good, but you cannot take home even one (they are all traped in the dot, and disappear within a few hundred ps, ~ 10^(-10) second. People have suggested to have dots connected by molecules, so the electrons could get out. However, when they are connected, they are not "dots" any more.
Slashdot Mirror
Can any one point out where this result was publsihed (other than the news release)? I would like to know the actual solar cell structure.
A calculated value of 42% should be compared to calculated values for other solar cells (e.g., for a single junction solar cell, the theoretical limit is ~32%, multijunctions are higher, it could be > 42%, depending on how many junctions you want to have). The 15-20% is industrial level for single junction cells, it is much higher in the lab (e.g., > 40% for a triple-junction solar cell). The current level of the quantum dot cell is ~ 1% in the lab.
The four major PV technologies are in fact 1. Si 2. CdTe thin film 3. CIGS thin film 4. III-V multijunction One could do concentrating PV for 1 and 4. TiO2 dye sensitized solar cell has around 10% lab efficiency and low cost, but generally unstable, thus, not in production. One of the nanowire solar cells is a proposal to improve such solar cell by replacing dye with a semiconductor shell. Quantum Dots (Which allow for up to 7 electrons to be created from 1 photon): not even reaching 1 % efficiency so far (anything can get that efficiency). Buy 1 get 6 free sounds good, but you cannot take home even one (they are all traped in the dot, and disappear within a few hundred ps, ~ 10^(-10) second. People have suggested to have dots connected by molecules, so the electrons could get out. However, when they are connected, they are not "dots" any more.