Methods and apparatus for real-time monitoring of cadmium ion during solution growth of cadmium sulfide thin films
AssigneeBoard of Regents, The University of Texas System
InventorsDavid Zubia, Rafael Ordonez
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Abstract
The present invention provides a reaction chamber to monitor a metal ion in solution during the formation of a metal-sulfide layer on a substrate. The reaction chamber houses a solution of an ammonium ion, a metal ion and a buffer. The reaction chamber includes an anion-selective electrode in the solution to monitor the metal ion that measures the metal ion during metal-ammonium complex formation, metal-thiourea complex formation, metal sulfide composition formation, metal sulfide layer formation or a combination thereof.
Claims12
A reaction chamber to monitor a metal ion in solution during the formation of a metal-sulfide layer on a substrate comprising:
- a reaction chamber that houses a solution, wherein the solution comprises an ammonium ion, a metal ion, and a buffer;
- and
- an anion-selective electrode in the solution to monitor the metal ion, wherein the anion-selective electrode measures the metal ion during metal-ammonium complex formation, metal-thiourea complex formation, metal sulfide composition formation, metal sulfide layer formation or a combination thereof.
A method for forming a metal layer on a solar cell substrate comprising the steps of:
- providing a reaction chamber in communication with a solution;
- combining an ammonium ion, a metal ion, and a buffer in the solution;
- monitoring the metal ion in the solution with an anion-selective electrode;
- forming a metal-ammonium complex in the reaction chamber;
- decomplexing the metal-ammonium complex;
- titrating with a thiourea composition to form a metal-thiourea complex;
- forming a metal sulfide composition from the metal-thiourea complex;
- and
- depositing a metal sulfide layer on a solar cell substrate in the reaction chamber.
A method of forming a metal sulfide layer comprising the steps of:
- providing a reaction chamber in communication with a solution;
- providing a substrate in communication with the reaction chamber and the solution;
- combining an ammonium ion, a metal ion, and a buffer in the solution;
- monitoring the metal ion in the solution with an anion-selective electrode;
- forming a metal-ammonium complex in the reaction chamber;
- decomplexing the metal-ammonium complex;
- titrating with a thiourea composition to form a metal-thiourea complex;
- forming a metal sulfide composition from the metal-thiourea complex;
- and
- depositing a metal sulfide layer on a solar cell substrate in the reaction chamber.
A method of identify cadmium sulfide film heterogeneous growth and cadmium sulfide powder homogenous precipitate comprising the steps of:
- providing a reaction chamber in communication with a solution;
- providing a substrate in communication with the reaction chamber and the solution;
- combining an ammonium ion, a cadmium ion, and a buffer in the solution;
- monitoring the cadmium ion in the solution with an anion-selective electrode to identify a heterogeneous cadmium sulfide film growth or a homogenous cadmium sulfide powder precipitate;
- forming a cadmium-ammonium complex in the reaction chamber;
- decomplexing the cadmium-ammonium complex;
- titrating with a thiourea composition to form a cadmium-thiourea complex;
- forming a metal sulfide composition from the cadmium-thiourea complex;
- and
- depositing a cadmium sulfide layer on a solar cell substrate in the reaction chamber.
A method of monitoring cadmium sulfide layer deposition on a substrate comprising the steps of:
- providing a reaction chamber in communication with a solution;
- providing a substrate in communication with the reaction chamber and the solution;
- combining an ammonium ion, a cadmium ion, and a buffer in the solution;
- monitoring the cadmium ion in the solution with an anion-selective electrode;
- forming a cadmium-ammonium complex in the reaction chamber;
- decomplexing the cadmium-ammonium complex;
- titrating with a thiourea composition to form a cadmium-thiourea complex;
- forming a cadmium sulfide composition from the cadmium-thiourea complex;
- and
- depositing a cadmium sulfide layer on a solar cell substrate in the reaction chamber.
A method of fabricating a semiconductor composition comprising the steps of:
- providing a reaction chamber in communication with a solution;
- providing a substrate in communication with the reaction chamber and the solution;
- combining an ammonium ion, a metal ion, and a buffer in the solution;
- monitoring the metal ion in the solution with an anion-selective electrode;
- forming a metal-ammonium complex in the reaction chamber;
- decomplexing the metal-ammonium complex;
- titrating with a thiourea composition to form a metal-thiourea complex;
- forming a metal sulfide composition from the metal-thiourea complex;
- and
- depositing a metal sulfide layer on a solar cell substrate in the reaction chamber.
Dependencies are inferred from the claim text.