Boron doping silicon with

Other reverse-bias annealing experiments have been published that can be analyzed in the same way. Tavendale et al. (1985) used 10 ft cm boron-doped silicon passivated by exposure to plasmas containing or 2H. Schottky diodes formed with such specimens showed breakup of BH under heating at 80°C with reverse bias however, there was a persistence of passivation in the first two or three microns that must be attributed to some sort of near-surface reservoir of hydrogen. This effect was absent in an annealing experiment on a junction diode with an -type surface... 

This layer is placed on top of a thicker layer of boron-doped silicon (P-layer with positive character). These layers are connected by the P-N junction. When sunlight strikes the surface of the PV cell, an electric field is generated, which provides momentum and direction to the light-stimulated electrons, resulting in a flow of current when the solar cell is connected to an electric load. 

Table 2.5. Fit parameters according to (2.24) for zinc oxide [67] in comparison with that of phosporous- and boron-doped silicon [103]...

In 1981 an efficiency of 7.5% was obtained for a p-i-n structure (3.3 mm2) in which the p layer was a boron-doped silicon-carbon-hydrogen alloy (a-Si C H) (Tawada et al., 1981). A further improvement in conversion efficiency to 8.5% was obtained in 1982 with a stacked junction structure (9 mm2) that utilized an amorphous silicon-germanium-hydrogen alloy (a-Si Ge H) in the back junction of three stacked p-i-n junctions (Nakamura et al., 1982). More recently, an efficiency of 10.1% has been achieved in a p-i-n structure (1.2 cm2) utilizing p-type a-Si C H as a window layer (Catalano et al., 1982). 

For a given type and orientation the etch rate of silicon in alkaline solutions is largely independent of doping concentration up to about 10 Vcm. At a doping level of about 2 x lO Vcm the etch rate of boron-doped silicon drastically decreases with increasing dopant concentration Reduction by as much as three orders of... 

Like the n-type semiconductors, silicon doped with boron is composed of neutral atoms and is uncharged. For each boron atom in the crystal there will be one electron fewer in the highest filled band of silicon. Because the valence band is now only partly full, boron-doped silicon is a better conductor than pure silicon. The current in p-type semiconductors is carried by the few mobile electrons in the valence band, and is proportional to the number of empty levels in this band. 

Semiconductors are typically manufactured by doping silicon with either phosphorus or boron. 

Arie et al. [116] investigated the electrochemical characteristics of phosphorus-and boron-doped silicon thin-film (n-type and p-type silicon) anodes integrated with a solid polymer electrolyte in lithium-polymer batteries. The doped silicon electrodes showed enhanced discharge capacity and coulombic efficiency over the un-doped silicon electrode, and the phosphorus-doped, n-type silicon electrode showed the most stable cyclic performance after 40 cycles with a reversible specific capacity of about 2,500 mAh/g. The improved electrochemical performance of the doped silicon electrode was mainly due to enhancement of its electrical and lithium-ion conductivities and stable SEI layer formation on the surface of the electrode. In the case of the un-doped silicon electrode, an unstable surface layer formed on the electrode surface, and the interfacial impedance was relatively high, resulting in high electrode polarization and poor cycling performance. 

To prepare porous silicon microarrays in the Laurell group, 380 pm-thick <100> silicon wafers were utilized. The p-type boron-doped wafer with a resistivity of 10-15 Qcm was mounted in an in-house-made electrochemical etch cell. The porosification was made in an electrolyte solution of HF/DMF 1 10, and the wafer was illuminated by a 100 W halogen lamp at a distance of 10 cm. A current density of 2 mA/cm was applied for 1 h. The macropores in the porous layer produced for protein microarrays typically measured 0.5-1.5 pm with a fine side branching network of nanopores (Ressine et al. 2005). 

In a solar cell, doping silicon with boron atoms produces... 

A photovoltaic cell (often called a solar cell) consists of layers of semiconductor materials with different electronic properties. In most of today s solar cells the semiconductor is silicon, an abundant element in the earth s crust. By doping (i.e., chemically introducing impurity elements) most of the silicon with boron to give it a positive or p-type electrical character, and doping a thin layer on the front of the cell with phosphorus to give it a negative or n-type character, a transition region between the two types... 

Figure 4.22 Schematic diagram of a field effect transistor. The silicon-silicon dioxide system exhibits good semiconductor characteristics for use in FETs. The free charge carrier concentration, and hence the conductivity, of silicon can be increased by doping with impurities such as boron. This results in p-type silicon, the p describing the presence of excess positive mobile charges present. Silicon can also be doped with other impurities to form n-type silicon with an excess of negative mobile charges.

Fig. 4.9 Cyclic voltammograms of silicon anodes of different crystal orientation (1015 crrf3, boron doped, versus a Pt pseudoreference electrode in 5% HF), with the characteristic...

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