Solr not able to return the correct product after searching by product code or other code

Hi, i wanted to indexing the products codes with solr using the springELValueProvider and precising the type of the indexed property as String, however when i try to search for a product using his code in the search bar i get a few unexpected results for the products. some unwanted content are also displaying. for example when i am going to search "abc def" then two product is showing one is "abc" and another is "abc def". same for colon also when i am searching "abc:def" then "abc" and "abc:def" both product is showing. schema.xml.

  <fieldType name="keyword" class="solr.TextField" positionIncrementGap="100">
              <analyzer>
                  <tokenizer class="solr.KeywordTokenizerFactory" />
                  <filter class="solr.LowerCaseFilterFactory"/>
              </analyzer>
          </fieldType>

 

      <dynamicField name="*_keyword" type="keyword" indexed="true" stored="true" />
      <dynamicField name="*_keyword_mv" type="keyword" indexed="true" stored="true" multiValued="true" />
 

can you guys explain where i am wrong. if any information please let me know. thanks in advance.