Zinc oxide with acicular structure, process for its production, and photoelectric conversion device

Abstract

A process for producing a zinc oxide acicular structure by growing an acicular zinc oxide on a substrate, the process comprising the steps of holding the substrate in an electrolytic solution in which at least zinc ions are present, and forming zinc oxide on the substrate by electrodeposition. The electrolytic solution contains at least one cosolute. Also, disclosed is a photoelectric conversion device comprising a charge transport layer having the zinc oxide acicular structure.

1 . A process for producing a zinc oxide acicular structure, the process comprising the steps of: 
 holding a substrate in an electrolytic solution; and    forming zinc oxide on the substrate by electrodeposition,    wherein the electrolytic solution comprises zinc ions and at least one cosolute.    
     
     
         2 . The process according to  claim 1 , wherein the cosolute comprises an organic solvent, a halide, a monomer, or a polymer of a monomer.  
     
     
         3 . The process according to  claim 2 , wherein said organic solvent is in a concentration of 10% or less as volume ratio to the electrolytic solvent.  
     
     
         4 . The process according to  claim 2 , wherein the halide is a salt of a halide, represented by the chemical formula: K—R, where R is Cl, Br or I.  
     
     
         5 . The process according to  claim 2 , wherein the halide is a salt of a halide, represented by the chemical formula: Na—R, where R is Cl, Br or I.  
     
     
         6 . The process according to  claim 4 , wherein the salt of a halide is in a concentration ranging from 0.001 mol/L to 1.0 mol/L.  
     
     
         7 . The process according to  claim 5 , wherein the salt of a halide is in a concentration ranging from 0.001 mol/L to 1.0 mol/L.  
     
     
         8 . The process according to  claim 2 , wherein the polymer is a water-soluble polymer.  
     
     
         9 . The process according to  claim 2 , wherein the monomer or the polymer thereof is in a concentration ranging from 0.01 g/L to 100 g/L.  
     
     
         10 . A cell which comprises an electrode comprising a zinc oxide acicular structure produced by the process according to  claim 1 .  
     
     
         11 . A photoelectric conversion device comprising: 
 an electron acceptor type charge transporting layer;    an electron donor type charge transporting layer; and    a light-absorbing layer provided between these charge transporting layers,    wherein the electron acceptor type charge transporting layer comprises a zinc oxide acicular structure, and    wherein the zinc oxide acicular structure is formed by electrodeposition on a conductive substrate in an electrolytic solution in which zinc ions and at least one cosolute are present.    
     
     
         12 . The photoelectric conversion device according to  claim 11 , wherein the cosolute comprises an organic solvent, a halide, a monomer, a polymer of a monomer, or a surface-active agent.