What is claimed is:
1. A collapsible tricycle for use of young children, comprising a front frame part connected to a front wheel and handlebars at a lower end and an upper end respectively;
a stationary frame part connected to said front frame part at a front portion;
a saddle;
a rear frame part;
a pair of rear wheels connected to a rear portion of said rear frame part; and characterized by
a pair of parallel extended walls formed on a rear portion of said stationary frame part; said extended walls having upper and lower pivotal holes for a front portion of said saddle, and a front end of a connecting rod to be pivoted to respectively by means of pivotal rods passing through said pivotal holes;
a pair of parallel extended walls formed on said rear frame part, and an interposed board part connected to upper edges of said walls of said rear frame part;
said walls of said rear frame part defining a front space at front portion, and defining a receiving space behind said front space; said interposed board part being formed in such manner as to allow said front space of said rear frame part to have an upper opening; said connecting rod being pivoted to second pivotal holes on front parts of said walls of said rear frame part from an rear end; said rear frame part being pivoted to said saddle from first pivotal holes formed on front parts of said walls thereof;
a bottom of a rear part of said saddle being supported on a front holding portion of said interposed board part of said rear frame part when said tricycle is in a stretched in-use position.
2. The collapsible tricycle for use of young children as claimed in claim 1, wherein a width of receiving space of said rear frame part is bigger than that of said rear portion of said stationary frame part such that said rear portion of said stationary frame part can be received in said receiving space when said rear frame part is moved close to said stationary frame part for collapsing said tricycle.
3. The collapsible tricycle for use of young children as claimed in claim 1, wherein said saddle has a receiving room at said rear part, and said front parts of said walls of said rear frame part have first and second engaging gaps formed on edges; said receiving room of said saddle receiving an engaging rod biased forwards of said saddle to a locking position by a spring and connected to a pull handle positioned outside said saddle; said engaging rod engaging said first engaging gaps to fix said tricycle in said stretched in-use position, and engaging said second engaging gaps to fix said tricycle in a folded position; said engaging rod being disengaged from said gaps by pulling said pull handle, thus allowing said saddle, said frame parts to pivot on each other.
4. The collapsible tricycle for use of young children as claimed in claim 1, wherein said rear frame part is pivoted to said saddle from said first pivotal holes by means of passing a pivotal rod through said first pivotal holes, and a pivotal hole of said saddle; two bushings being each positioned at one end of said pivotal hole of said saddle for said pivotal rod to pass through, thus preventing said rear frame part from moving sideways relative to said saddle.
5. The collapsible tricycle for use of young children as claimed in claim 3, wherein a rear part of said spring is secured in position by a securing block formed in said saddle, and said saddle has elongated slots for allowing two ends of said engaging rod to pass through, thus guiding a movement of said engaging rod.
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 multicell photovoltaic monolithic semiconductor device for generating electrical energy, comprising:
an undoped substrate common to all cells of the multicell photovoltaic monolithic semiconductor device, the substrate having a first surface for receiving infrared and near-infrared photon energy from an emitter heat source in a near field and a second surface opposite the first surface forming an interface with a plurality of thin lateral collection region layers;
the plurality of thin lateral collection region layers for generating electron-hole pairs from absorbed photon energy from the near field emitting surface;
N+ collection junctions and P+ ohmic contact regions formed in a surface of each of the plurality of thin lateral collection region layers opposite the substrate, the N+ collection junctions for collecting electrons and the P+ ohmic contact regions for collecting holes from the electron-hole pairs traveling laterally in the plurality of thin lateral collection region layers;
isolation cuts between individual cells of the multicell photovoltaic device, the individual cells formed by isolating adjacent P+ ohmic contact regions and N+ collection junctions within each of the plurality of thin lateral collection region layers;
dielectric layers formed on the surface of each of the plurality of thin lateral collection region layers opposite the substrate and on surfaces of the isolation cuts; and
metal interconnections and vias in the dielectric material for interconnecting N+ collection junctions and P+ ohmic contact regions within and between individual cells in an array for forming the multicell photovoltaic monolithic semiconductor device.
2. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein each individual cell of the multicell photovoltaic monolithic semiconductor device includes one or more diode configurations, each diode configuration includes an N+ collection junction and a P+ ohmic contact region.
3. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the first surface of the substrate is separated from the emitting heat source by less than one micron.
4. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the dielectric layers and metal interconnections comprise a back surface reflector for recycling below band photons back to the emitter heat source.
5. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the dielectric layers and metal interconnections comprise a back surface reflector for providing a second pass for reflected in-band photons to be absorbed in the plurality of thin lateral collection region layers.
6. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein multiple cells may be fabricated and interconnected as a monolithic large scale array.
7. The multicell photovoltaic monolithic semiconductor device of claim 1, further comprising isolation of the plurality of thin lateral collection region layers from a heterojunction of the substrate by a thin layer of medium doped material in the vicinity of the interface of the plurality of thin lateral collection region layers and the second surface of the substrate to form a diffusion barrier to keep minority carriers from migrating into the substrate from the plurality of thin lateral collection region layers where they would be lost by recombination.
8. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein lateral conduction takes place by diffusion of carriers between ohmic contacts and along interconnecting metallization layers, with no lateral conduction layers buried within the device.
9. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein electron-hole pairs created in the plurality of thin lateral collection region layers by impinging photons travel laterally to collection junctions and ohmic contact regions.
10. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the substrate first surface provides a smooth flat surface for forming a near-field gap with a photon-emitting surface.
11. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the plurality of thin lateral collection region layers are germanium semiconductor materials, wherein material bandgaps provide a good match for converting energy from a low temperature heat source.
12. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the undoped substrate is selected from the group consisting of semi-insulating gallium arsenide, silicon, and indium phosphide.
13. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the plurality of thin lateral collection region layers is selected from the group consisting of N-type and P-type material.
14. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the plurality of thin lateral collection region layers is selected from the group consisting of germanium, GaSb, GaInSb, GaInAs, GaInAsSb and InGaAs.
15. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the photovoltaic device is a thermophotovoltaic device.
16. The multicell photovoltaic monolithic semiconductor device of claim 1, wherein the substrate first surface receives infrared and near-infrared photon energy from an emitter heat source in a far field.
17. A multicell photovoltaic monolithic semiconductor device for generating electrical energy, comprising:
an undoped substrate common to all cells of the multicell photovoltaic monolithic semiconductor device;
a plurality of thin lateral collection region layers for generating electron-hole pairs from absorbed photon energy;
N+ collection junctions and P+ ohmic contact regions formed in a surface of each of the plurality of thin lateral collection region layers, the N+ collection junctions for collecting electrons and the P+ ohmic contact regions for collecting holes from the electron-hole pairs traveling laterally in the plurality of thin lateral collection region layers;
isolation cuts between individual cells of the multicell photovoltaic device, the individual cells formed by isolating adjacent P+ ohmic contact regions and N+ collection junctions within each of the plurality of thin lateral collection region layers;
dielectric layers formed on the surface of each of the plurality of thin lateral collection region layers on surfaces of the isolation cuts; and
metal interconnections and vias in the dielectric material for interconnecting N+ collection junctions and P+ ohmic contact regions within and between individual cells in an array for forming the multicell photovoltaic monolithic semiconductor device.