This I do
by melting it upon a plate of metal with which it will form a chemical
combination, sufficient, at least, to cause the selenium to adhere and
make a good electrical connection with it. The other surface of the
selenium is not so united or combined, but is left in a free state, and a
conductor is subsequently applied over it by simple contact or pressure.
During the process of melting and crystallizing, the selenium is
compressed between the metal plate upon which it is melted and another
plate of steel or other substance with which it will not combine. Thus by
the simultaneous application and action of heat, pressure, chemical
affinity, and crystallization, it is formed into a sheet of granular
selenium, uniformly polarized throughout, and having its two surfaces in
opposite phases as regards its molecular arrangement. The non-adherent
plate being removed after the cell has become cool, I then cover that
surface with a _transparent conductor of electricity_, which may be a
thin film of gold leaf. Platinum, silver, or other suitable material may
also be employed. The whole surface of the selenium is therefore covered
with a good electrical conductor, yet is practically bare to the light,
which passes through the conductor to the selenium underneath.
Pages:
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95