diff --git a/include/cantera/thermo/SemiconductorPhase.h b/include/cantera/thermo/SemiconductorPhase.h
index fb97284c4..9364ac996 100644
--- a/include/cantera/thermo/SemiconductorPhase.h
+++ b/include/cantera/thermo/SemiconductorPhase.h
@@ -21,12 +21,16 @@ const int cHole = 1;
  * @ingroup thermoprops
  *
  * Class SemiconductorPhase represents electrons and holes in a semiconductor.
+ * @deprecated Broken and unused. To be removed after Cantera 2.3.
  *
  */
 class SemiconductorPhase : public ThermoPhase
 {
 public:
-    SemiconductorPhase() {}
+    SemiconductorPhase() {
+        warn_deprecated("class SemiconductorPhase",
+                        "To be removed after Cantera 2.3.");
+    }
     SemiconductorPhase(std::string infile, std::string id="");
 
     SemiconductorPhase(const SemiconductorPhase& right) {
diff --git a/src/thermo/SemiconductorPhase.cpp b/src/thermo/SemiconductorPhase.cpp
index c319af07f..90f7c7afe 100644
--- a/src/thermo/SemiconductorPhase.cpp
+++ b/src/thermo/SemiconductorPhase.cpp
@@ -11,7 +11,10 @@ static doublereal JoyceDixon(doublereal r)
 }
 
 SemiconductorPhase::SemiconductorPhase(std::string infile,
-                                       std::string id_) {}
+                                       std::string id_) {
+    warn_deprecated("class SemiconductorPhase",
+                    "To be removed after Cantera 2.3.");
+}
 
 void SemiconductorPhase::getChemPotentials(doublereal* mu) const
 {