What is claimed is:
1. A stacked photovoltaic device comprising:
at least one pair of a first photovoltaic device and a second photovoltaic device stacked in order from a light incident side; and
a selective reflection layer formed between the at least one pair of the first photovoltaic device and the second photovoltaic device and adapted to electrically connect therebetween,
wherein the selective reflection layer has a sheet resistance of 100 k or more and 100 M or less.
2. The stacked photovoltaic device according to claim 1, wherein the selective reflection layer has a sheet resistance of 100 k or more and 50 M or less.
3. The stacked photovoltaic device according to claim 1, wherein the selective reflection layer has a sheet resistance of 5 M or more and 50 M or less.
4. The stacked photovoltaic device according to claim 1, wherein the selective reflection layer has a conductivity in a thickness direction of a film which is larger than a conductivity in an in-plane direction of the film.
5. The stacked photovoltaic device according to claim 1, wherein the selective reflection layer comprises a deposited film formed of metal oxide.
6. The stacked photovoltaic device according to claim 1, wherein the first photovoltaic device has at least a pin-type junction and an i-type layer thereof comprises amorphous Si:H.
7. The stacked photovoltaic device according to claim 1, wherein the second photovoltaic device has at least a pin-type junction and an i-type layer thereof comprises Si having crystallinity.
8. The stacked photovoltaic device according to claim 1, wherein the second photovoltaic device has at least a pn-type junction and a p-type semiconductor and an n-type semiconductor comprise one of monocrystalline Si, polycrystalline Si, and Si having crystallinity.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A microscale driving unit comprising:
a support member;
a driven member;
a first elongated piezoelectric actuator extending in a first direction from a base end fixed to the support member, said first elongated piezoelectric actuator being fixed to the driven member at a tip end of the actuator;
a second elongated piezoelectric actuator extending in a second direction from a base end fixed to the support member, said second elongated piezoelectric actuator being fixed to the driven member at a tip end of the actuator, said second direction being set antiparallel to the first direction;
a first electrically conductive member connecting the base end of the first elongated piezoelectric actuator to the tip end of the second elongated piezoelectric actuator; and
a second electrically conductive member connecting the base end of the second elongated piezoelectric actuator to the tip end of the first elongated piezoelectric actuator.
2. The microscale driving unit according to claim 1, wherein said electrically conductive members are made of wire bonding materials.
3. The microscale driving unit according to claim 2, wherein said elongated piezoelectric actuator is made of a layered material, said layered material comprising:
first inside electrode layers extending from exposed ends near the base end toward the tip end;
second inside electrode layers extending from exposed ends near the tip end toward the base end between the adjacent ones of the first inside electrode layers; and
active layers interposed between the first and second inside electrode layers.
4. The microscale driving unit according to claim 3, wherein said elongated piezoelectric actuator comprises:
a first terminal electrode attached to the exposed end near the base end; and
a second terminal electrode attached to the exposed end near the tip end.
5. The microscale driving unit according to claim 4, wherein said active layer is made of PNN-PT-PZ.
6. The microscale driving unit according to claim 5, wherein said first and second elongated piezoelectric actuators are arranged symmetrically around a rotational axis of the driven member.